The Sea Shore

by William S. Furneaux

Outdoor Work

Assuming that the reader is one who desires to become intimately acquainted with the wonderful and varied forms of life to be met with on the sea shore, or, hoping that he may be lured into the interesting and profitable pastimes of the sea-side naturalist, we shall now devote a chapter to the consideration of the appliances required for the collection and examination of marine life, and to general instructions as to the methods by which we may best search out the principal and most interesting objects of the shore.

First, then, we shall describe the equipment of an enthusiastic and all-round admirer of Nature—he who is interested in plant forms from the flowering species down to the ‘meanest weed that grows,’ and is always ready to learn something of any member of the animal world that may happen to come within his reach. And this, not because we hope, or even desire, that every reader may develop into an all-round naturalist, but so that each may be able to select from the various appliances named just those which would be useful for the collection and observation of the objects which are to form his pet study.

The most generally useful of all these appliances is undoubtedly some kind of case of the ‘hold-all’ type, a case into which specimens in general may be placed for transmission from the hunting-ground in order that they may be studied at leisure, and we know of nothing more satisfactory than the botanist’s ‘vasculum.’ This is an oblong box of japanned tin, fitted with a hinged front, and having both handle and strap, so that it can be either carried in the hand or slung over the shoulder. Of course almost any kind of non-collapsible box or basket will answer the purpose, but we know of no utensils so convenient as the one we have named. It is perfectly satisfactory for the temporary storage of the wild flowers gathered on the cliffs, as it will keep them moist and fresh for some considerable time; and for the reception of sea weeds of all kinds it is all that could be desired, for it will preserve them in splendid condition, and is so constructed that there is no possibility of the inconvenience arising from the dripping of salt water on the lower garments. Then, as regards marine animal-life in general—starfishes, urchins, anemones, molluscs, crustaceans, fishes, &c.—these may be conveyed away in it with a liberal packing of moist weeds not only without injury, but in such a satisfactory condition that nearly all may be turned out alive at the end of a day’s work; and this must be looked upon as a very important matter to him who aims at becoming a naturalist rather than a mere collector, for while the latter is content with a museum of empty shells and dried specimens, the former will endeavour to keep many of the creatures alive for a time in some kind of artificial rock pool in order that he may have the opportunity of studying their development and their habits at times when he has not the chance of visiting the sea shore for the purpose.

Fig. 13.—The Vasculum

But although the vasculum is so generally useful for the temporary storage and the transmission of the objects collected, yet it is not in itself sufficient for all purposes. There are many marine animals so small—but none the less interesting because they are small—that they would probably be lost in a case containing a mass of sea weeds with various larger creatures. These should be placed in small well-corked bottles, and temporarily preserved in a little sea-water, or, preferably, a tuft of one of the delicate weeds so common in our rock pools. Others, again, though they may be larger, are of so fragile a nature that they should be isolated from the general stock on that account alone. Instead of bottles or tubes, small tin boxes may be used, and these have the advantage of being unbreakable, though, of course, they will not hold water. This, however, is of no consequence, as most marine animals may be kept alive for some time in moist sea-weed quite as well as in water.

When small animals are required for structural examination only, they may be put into methylated spirit as they are taken, and when stored in this way a much larger number may be put into the same receptacle; hence the collector will often find it convenient to have a small supply of this liquid while at his work.

A strong pocket-knife is essential for sea-side work. It serves to remove those molluscs that adhere firmly to the rocks by suction, and also others that fix themselves by means of a byssus of silken fibres, as is the case with mussels. It will also be employed in the removal of acorn barnacles, anemones, and small tufts of algæ, and may be useful in cutting through the stouter weeds. Small sponges and other low forms of life often form incrustations on the solid rock, and may be peeled off with the aid of a knife. In the case of the last-named, however, as well as with the anemones and other fixed animals, it is often far more satisfactory to remove a small portion of the rock itself with the animal attached, and for this purpose a small hammer will be of great service.

A strong net of some kind is necessary in searching the rock pools, and as suitable nets are, we believe, not to be obtained of the dealers in naturalists’ appliances, it devolves on one to manufacture a net according to his requirements.

The simplest form of net may be made by bending a piece of stout galvanised iron wire into the form here shown (fig. 14), and firmly wedging the two straight ends in a short piece of strong metal tube which will also serve as a ferrule for the attachment of a tough handle. Such a circular frame although satisfactory for a net to be used in fresh-water ponds and streams, is not nearly so suitable for the irregular rocky pools to be met with on the sea coast, for it will not enable one to search the numerous corners and crevices into which many marine creatures will retire on being disturbed, but it may be greatly improved by bending the side opposite the ferrule into a moderately sharp angle and then turning the angle slightly upward, as shown in fig. 15.

Fig. 14.—Wire Ring for Net

Fig. 15.—Net Frame with Curved Point

Another very convenient net frame may be made by bending the wire into a rhomboidal form (fig. 16), the ferrule being attached by means of two short, straight ends at one of the angles. The opposite angle will serve the purpose of searching into the crannies of the rocks, while the straight sides will prove very useful in removing the objects that lie on the sandy bottoms so commonly seen in rock pools. The semicircular net shown in fig. 18 will also prove useful for working on sands or for scraping the flatter surfaces of weed-covered rocks.

Fig. 16.—Rhomboidal Frame for Net

The material of the net should be some kind of strong gauze, or a loosely-woven canvas. Leno answers very well, but is somewhat easily torn, and will have to be frequently renewed. This, however, may be avoided to a great extent if, instead of sewing the gauze directly round the wire, a strip of strong calico be first attached to the frame, and the gauze then sewn to the calico; for it will be understood that any fragile material placed round the wire will soon be worn through by friction against the rugged surfaces of the rocks and stones. The net itself should not be very deep, and should have no corners; and as to the length of the handle, that will be determined by the fancy of the collector, or by the character of the ponds to be searched, but a tough walking-stick with a crook handle will generally answer all purposes, the crook being itself frequently useful for removing the larger weeds and other obstructions.

Fig. 17.—Rhomboidal Net

Fig. 18.—Semicircular Net

Fig. 19.—The Dredge

Although the net, as above described, will answer the requirements of nearly all young collectors, yet there may be some, who, not satisfied with the exploration of the rocks and pools exposed when the tide is out, desire to know something of the creatures that live entirely beyond low-water mark, where the water is generally too deep for work with a hand net. To such we recommend a small dredge that may be lowered from a boat and then drawn along the bottom. A good form of dredge is shown in fig. 19, and a little skill and ingenuity will enable anyone to construct one with the help of our illustration; but, seeing that the best work is to be done on rough bottoms, it is absolutely necessary that both frame and net should be made of the stoutest materials that can be conveniently employed.

Fig. 20.—The Crab-pot

Those who have ever accompanied a fisherman while taking a pull round to examine the contents of his crab or lobster pots will probably have noticed what strange creatures, in addition to the edible crabs and lobsters, sometimes find their way into the trap. These creatures are often of great interest to a young naturalist, and it will repay him to take an occasional trip with a fisherman in order to obtain them; or, still better, to have a crab-pot of his own. The writer has obtained many good specimens by means of an inexpensive trap, on the same principle as the ordinary crab-pot, made from an old metal bird-cage of rather small size. The bottom was removed, and a very shallow bag of thick canvas fixed in its place; and some of the wires were cut, and bent inwards so as to allow the easy entrance of moderately large crustaceans and other creatures, while at the same time they served as a barrier to their escape. Such a trap, baited with pieces of fish, and let down to a rocky bottom, will enable the young naturalist to secure specimens that are seldom seen between the tide-marks; and the animals thus obtained will include not only those larger ones for which the opening was made, but also a variety of smaller creatures that may enter between the wires of the cage. Some of the latter may, of course, escape by the same way as the trap is being hauled up for examination, but this is not so likely to occur if the canvas bottom is of a material so loosely woven that water can pass through it very freely. It will, of course, occur to the reader that the insertion of a stone or other weight will assist in sinking the trap; also that the ordinary door of the cage forms a ready means by which the captives may be removed.

Fig. 21.—An old Bird-cage used as a Crab-pot

One thing more: make it a rule never to go out collecting natural objects of any kind without a note-book and pencil. This, to the beginner who is anxious to get to his work, with the idea only too prevalent with the amateur that the success of his labours is to be measured only by the number of specimens obtained, may seem quite an unnecessary part of the equipment. But it must be remembered that there is much to observe as well as much to collect on a well-selected coast; and that without the aid of the book and pencil a great many of the observations made will be forgotten, and thus much interest that would otherwise be attached to the objects permanently preserved will be lacking.

The above appliances include the only necessary equipment of the sea-side naturalist, with the exception of a few required for occasional use in connection with the species of a somewhat restricted habitat, and the outfit of the sea angler. The former will be dealt with in the chapters where the species concerned are described, while the subject of sea angling is of such general interest that we propose to devote a short chapter exclusively to it.

It may seem hardly necessary to discourse on the nature of the attire most suitable for sea-side work, since the majority will readily form their own opinions on this matter, but perhaps a few words of advice to the inexperienced may not be altogether out of place. First, then, make it a rule to wear no clothing of any value. The work will lead the enthusiast over slippery weeds, on treacherous boulders, over rocks covered with sharp acorn shells, and among slimy and muddy stones, and many a slip may occur in the course of a day’s work. Large pockets specially but simply made by sewing square pieces of lining on the inside of an old jacket are a great convenience; a cap rather than a brimmed hat should be worn unless the latter be considered essential for protection from a burning summer’s sun; and a pair of old shoes, preferably with rubber soles, are just the thing for both rough and slippery rocks, as well as for wading through shallow waters. Other details we can safely leave to the fancy of the reader himself.

Now comes the most important question ‘Where shall we go?’ Fortunately we are favoured with a great extent of coast-line considering the area of our country, but the character of the coast is so diversified, both with regard to its scenery and its life, that the naturalist will do well to carefully select his locality according to the objects he desires to study. The east coast of England is not generally noted either for variety or abundance of marine life, and the same is true both of the south-east and a large portion of the south coast. In some places the beach is formed of an unbroken stretch of sand on which one may walk for miles without seeing any sign of life, with the exception of an occasional empty shell and a few fragments of dried sea-weed washed in by the breakers during a recent storm; while at the same time the cliffs, if such exist at all, are not very generous in their production of the fauna and flora that are characteristic of the shore. But even on the coasts referred to there are, here and there, isolated spots where the uplands jut into the sea, giving rise to bold promontories, at the foot of which are the fallen masses of rock that afford protection to a moderate variety of truly marine life, while the rough bottoms beyond yield numerous interesting forms that may be secured by means of the dredge or suitable traps. Such spots are to be found where the chalk hills abut on the sea, as at Flamborough and Beachy Head, but it is in the neighbourhood of Weymouth that the English coast really begins to be of great interest to the naturalist. From here to the Land’s End almost every part of the shore will yield a great variety of life in abundance, and the same is true of the rocky coasts of the west, and also of the more rugged shores of the Isle of Wight. As an ideal hunting-ground one cannot do better than to select one of the small fishing towns or villages on the rocky coasts of Devon and Cornwall. With such a spot as his headquarters the most enthusiastic sea-side naturalist will find ample employment. The exposed rocks and rock pools yield abundance of life; and if these be searched when the tide is out, there will remain plenty of sea angling and other employments to occupy him at other times.

We will now describe the actual work of the sea-side naturalist, giving the necessary instructions for the observation and collection of the various living things he will meet with.

First, then, with regard to work on the cliffs, a very few words will suffice; for, seeing that the objects of interest to be met with here will consist principally of the various flowers that are peculiar to or characteristic of the sea shore, and certain insects and other creatures more or less partial to a life on the cliffs, we may regard these as coming within the range of the general work of the botanist, entomologist, &c.; and since instructions for the collection and preservation of such objects have already been given in former works of this series, we may pass them over at once in order to deal with those objects which are essentially marine.

It has already been hinted that the right time for collecting on the shore is when the tide is at its lowest; and in order that the best work may be done the collector should consult the local tide-tables, or calculate, if necessary, the time of high tide from the establishment of the port; and, of course, the period of spring tides should be selected if possible. The time during which work should continue must be regulated according to the enthusiasm of the collector or the time at his disposal, but, as a rule, it is advisable to be on the scene of action about three hours before the time of low tide, with a determination to work continuously until the lowest ebb of the water.

On reaching the beach it is always advisable to start by examining the line of miscellaneous material at high-water mark, along which may be found quite a variety of objects, more or less interesting, which have been washed in by the breakers, especially just after a storm, together with numerous scavengers of the shore that perform a most useful work in devouring the decomposing organic matter that would otherwise tend to pollute the air.

Here we may find many useful and interesting objects of both the animal and vegetable worlds. Among the former are the empty shells of both univalve and bivalve molluscs, some of which are more or less worn by the action of the waves, while others are in splendid condition for examination and study. Here, too, are various species of sea firs and the skeletons of sponges; the shell of the cuttle-fish, and occasionally a cluster of the eggs of this creature—the sea-grapes of the fishermen; also the egg-cases of the skate and the dog-fish—usually empty, but sometimes enclosing the young animal still alive; and, lastly, we frequently meet with portions of the skeletons of fishes in a perfect state of preservation, the animal matter having been cleared away by the combined action of the scavengers previously referred to. Then, as regards the vegetable world, we often find beautiful specimens of sea-weeds along the high-water mark, some of which are rarely met with in the rock pools, since they are species that have been detached from beyond the line of low water, and washed up by the breakers.

On turning over the debris thus thrown on the beach we intrude on the privacy of numerous living creatures which immediately scamper away to find a new hiding-place. These consist principally of sand-hoppers, but occasionally we find members of the insect world engaged in the same useful work in addition to the numerous flies that perform their office of scavengers in the bright sunshine on the top of the matter that supplies them with food.

It will be interesting to capture a few of these scavengers, and to compare them with others of the same order obtained from different localities. Thus, the flies may be compared with the more familiar house fly, and the sand-hoppers of high-water mark with similar crustaceans to be afterwards obtained lower on the beach.

Attention should now be given to the rocks left exposed by the retreating tide, and it is here that the real work begins. Examine each rock pool as soon as possible after it is no longer disturbed by the waves. Remove any tufts of corallines or other weeds required for study or preservation, and simply place them, pro tem., in the vasculum or other receptacle provided for the purpose. These will form a useful protective packing for other objects that are to be carried away, so that it will be advisable to secure a moderate amount rather early, even though they may not be required for any other purpose. Live molluscs, crabs, small fishes, &c., may all be put in the receptacle with this weed, and all will probably be still alive after the collecting and the homeward journey have been completed. Probe the corners of the pool with the point of the net, and also sweep the net upward among the weeds to remove any creatures that seek shelter among the fronds. Tufts of corallines and other weeds should be searched for the small and delicate starfishes that live among them, and any stones that may cover the bottom of the pool should be lifted. Anemones may be removed from the rocks by means of a rather blunt knife; but, if possible, it will be better to chip off a small piece of the rock with the anemone attached to it, and wrap it lightly round with a tuft of soft weed previous to placing it in the collecting case.

A number of rock pools should be searched in this manner, but those chosen should vary as much as possible in general character. All very small and delicate objects should be isolated from the general stock, and placed, with the usual packing material, either in tin boxes or small wide-mouthed bottles; and if any animals taken are not required alive, but only for preservation, they should be preferably killed at once and then stored in a separate case. Some creatures are easily killed by simply dropping them into a bottle of fresh water, but others should be covered with methylated spirit. It should be mentioned, however, that the natural appearance of some of the crustaceans is quite destroyed by strong spirit, which soon makes them look as if they had been boiled. Some species are changed in this way much more readily than others; and, until sufficient experience has been gained to enable the young collector to distinguish between them, it will be advisable to kill and temporarily preserve crustaceans in spirit that has been considerably diluted with water—about two parts of water to one of spirit, for example. Further, there are certain fragile starfishes that have a way of breaking themselves into pieces when dropped into spirit, or even when suddenly disturbed in almost any other manner. These must always be handled gently, and if it is required to kill them for preservation, the best way will be to put them in a little salt water, and then gradually add fresh water until the desired result is obtained.

Perhaps the most productive of all sea-shore work is the turning over of the stones of various sizes near the low-tide mark, and the examination of the chinks and sheltered hollows of the rocks that are left uncovered for but a short period. This work should be carried on as near the water’s edge as possible, closely following the receding tide; and the collector must now be prepared with a number of small bottles or tins for the isolation of small and delicate specimens. He must also be on the alert for numerous examples of protective resemblance, in which the animals concerned so closely resemble their surroundings in colour and general character of surface that they are detected only by careful observation, while the difficulty of identification is still further increased in instances where the creatures remain perfectly still even when disturbed.

Fig. 22.—A Young Naturalist at Work

Under the stones all manner of animals—fishes, crustaceans, worms, molluscs, starfishes, anemones, &c.—will be hiding until covered by the next tide. Some of these will be found on the ground beneath the stones, and others attached to the under surfaces of the stones themselves; therefore both should be carefully examined, attention being given at first to the more active species that hurry away with all speed towards a new shelter as soon as they find themselves exposed to the light; the less active creatures may then be secured at leisure.

The tide will not allow the collector a great deal of time in which to turn over the most productive stones—those close to the low-water mark, so there is but little opportunity of observing the movements and other interesting habits of many of the animals found; hence it is advisable to secure a good variety of living specimens, especially of the less familiar species, in order that they may be placed in some kind of aquarium, temporary or otherwise, for observation at home.

Fig. 23.—A good Hunting-ground on the Cornish Coast

One thing more remains to be done while the tide is well out, and that is to examine the weed-covered rocks near the water’s edge. Lift the dangling weeds and carefully search the rocks for those low forms of animal life that form incrustations on the surface, as well as for new species of anemones, sea firs, &c. Lastly, look well into the dark and narrow chinks of the rocks, for here several species of lowly animals that are hardly met with elsewhere may be found, and also certain crustaceans that delight to squeeze their bodies into the remotest corner of a sheltered niche.

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CHAPTER III
SEA ANGLING

We do not propose dealing with this subject from the point of view of the angler, but rather that of the naturalist. The former is actuated principally, if not entirely, by the mere love of sport; or, it may be, to a great extent by the desire to obtain a supply of fish for food; and he generally estimates the success of his expeditions not by the number of species captured, but by the total weight of his catch, no regard being paid, as a rule, to the inedible specimens. The naturalist, however, does not desire weight, or sweetness of flesh. He works the greatest possible variety of habitats, with the object of determining the number of species inhabiting the locality and of learning as much as possible of their general form, habits, and adaptations of structure to habits. His success is measured by the number and variety of species caught, and he pays but little attention to superiority of size or weight, or to the estimated market value of his haul. The element of sport may enter more or less largely into the pleasure of his occupation, but the main end in view is to learn as much as possible of all the species obtainable.

Further, our remarks will not include the subject of the different kinds of fishing usually resorted to by sea anglers, but will be confined almost exclusively to the simple means of catching the common species that frequent the immediate neighbourhood of the shore.

If the reader will follow the general instructions given in Chapter II. on the outdoor work of the marine naturalist, he will undoubtedly make the acquaintance of a considerable variety of interesting species which may be captured in the rock pools, found under stones at low tide, or obtained by means of a small dredge; but his knowledge of our littoral fishes may be appreciably extended by the occasional employment of rod and line from rocks and piers, or from a small boat in close proximity to the shore.

The appliances required are of a very simple nature, and not at all costly. The long, heavy rod and strong tackle of the sea angler and professional fisherman are not at all essential to our purpose, for our work will be confined almost exclusively to shallow water, and the fish to be caught will be chiefly of small size. True it is that one may occasionally find his light tackle snapped and carried away by the unexpected run of a large fish, for cod and other large species often approach close to the shore, and bite at baits intended for the smaller fish that make their home among the partly submerged rocks of the coast; but such surprises will not frequently occur, and the young naturalist may learn all he wants to know of the fishes of our shallow waters with the aid of a light rod of about nine or ten feet and one or two light lines of no great length.

It must not be understood, however, that we assume the reader’s disinclination to know anything of the inhabitants of deep water, but rather that we consider the whole subject of deep-sea fishing quite beyond the scope of this work. It is a fact that quite a large number of species, the forms and habits of which are extremely interesting, live exclusively on deep bottoms. These should undoubtedly be studied by all who are interested in the various phases of marine life; but unless the reader is prepared to practise sea fishing in all its branches—to put his trust in the restless sea, supplied with all the necessary heavy gear, and to risk those internal qualms that arise from the incessant swaying of the boat on open waters, he should make arrangements with the professional deep-sea fisher—preferably a trawler—for the supply of those disreputable species that invariably form part of the haul, while the better-known food fishes can always be obtained from dealers for purposes of study.

On one occasion we had a rather unique and very successful interview with a friendly trawler. She was sailing slowly towards her station in a south-western fishing port, while two of her crew were clearing her nets, and throwing all refuse into the sea. We rowed behind her in order to see the nature of the rejected portion of the haul, and finding that it included specimens of interesting fishes of ill repute, dead but perfectly fresh, we followed her track, and collected a few for future examination. Presently our movements were watched from aboard, and we were invited to pull up to larboard, where a short explanation as to our wants led to the acquisition of quite a variety of deep-sea life, including several species of fishes not often seen on land, crabs, shelled and shell-less molluscs, worms, star-fishes, and various lowly organised beings, many alive and in good condition, together with several good food fishes thrown in by way of sympathy. There is no doubt that a naturalist can obtain much more deep-sea life with the aid of a friendly trawler than by any amount of ‘fishing’ with ordinary tackle from a boat; and this without the necessity of going to sea at all, if he will only take the opportunity of examining the nets as the boats are stranded on their return.

But now to return to our angling:—We have to provide a light rod, about ten feet long, with a winch, and a line of twisted silk or other thin but strong material; also a light hand line, and a supply of gut, leads, shot, and hooks, together with one or two small floats, and a few bait boxes.

We do not, as a rule, recommend the amateur angler to use both rod and hand line at the same time, for the attempt to do this leads to the neglect of both. In the end it is not likely to lead to any gain, so many fish being lost through the inability to strike at the moment a bite is given, and so much time having to be devoted to the baiting of hooks rather than to the direct management of the lines. In most cases the rod is much more convenient than the hand line. The young collector will meet with the greatest variety of species in rocky and weedy places, where abundant shelter exists for those fishes that prefer to keep well under cover, and any attempt with a hand line in such spots will certainly lead to frequent loss of hooks, and often of lead, line, and temper. Such a line must be reserved for fishing on sandy bottoms, while the ten-foot rod recommended will enable the angler to do good work in the rockiest parts without much danger of fouling; and, in fact, to fish anywhere along the coast.

The arrangement of hooks and lead must necessarily depend on the character of the place to be worked, but in all cases we strongly recommend no such multiplicity of hooks as is made use of by fishermen and others who fish for food. In their case the use of so many hooks often pays them well; but, as we have previously hinted, the naturalist does not desire quantity of fish so much as variety of species. Further, there is no necessity to make his work heavy and arduous. His desire is not to spend an undue proportion of his time in baiting hooks, but to have his line so under control that he is ready to strike at any moment, and to be able to alter the conditions of his work as often as his ideas or the conditions change.

In rugged and weedy places the hooks must be kept free from rocks and weeds. This may be done by letting down the rod line with a lead at the bottom, and one or two hooks fastened to gut at such a level as to keep quite clear of weeds. A much better arrangement, and one which we ourselves almost invariably employ, consists of a light lead, as a rule not exceeding an ounce in weight, fastened at the end of the line, and below it a few feet of gut terminating in a single hook. With such tackle it is of course necessary to determine previously the depth of the water, in order to adjust the line to such a length that the hook keeps clear of rocks and weeds, and a float may be used if desired.

Fig. 24.—Round Bend Hook with Flattened End

We do not recommend a float for the general work of the marine collector, for it is a decided advantage to be prepared to bring the bait to any level from bottom to surface, especially when the water is so clear that the fish may be seen swimming, in which case one is often impressed with the desire to capture a specimen in order to establish its identity, and for such work as this a float is superfluous. If, however, a float is used, it should be a sliding one, so that it may be adapted to the rising and falling of the tide.

Fig. 25.—Limerick Hook, eyed

Of hooks there is a great variety to choose from, differing in the form both of the curve and of the end of the shank. As to the curve, those with a decided twist are best adapted to our purpose, chiefly on account of the fact that sea fishes generally have larger mouths than fresh-water species of the same size, and are consequently better held with a twisted hook. The shanks of sea hooks are either flattened or eyed, and each is as good as the other providing the snood is firmly attached; but some amateurs find a greater difficulty in attaching the snood to the former than to the latter.

Gut snoods are recommended for our purpose, and fig. 26 shows one method by which they may be fastened to a flattened shank, while fig. 27 illustrates the figure-of-eight knot by means of which the eyed shank may be firmly secured. The gut should be soaked for some hours in cold water previous to tying, and it may be kept soft for some considerable time by giving it a few hours’ immersion in a solution of glycerine—about one part of glycerine to four or five parts of water.

Fig. 26.—Method of attaching Snood to Flattened Hook

Small hooks will be most suitable for our purpose; and if the reader finds any difficulty in attaching the snood firmly, he may purchase suitable hooks ready mounted on gut, though, of course, these are more expensive than the flattened or eyed hooks generally used for sea-fishing. Such small and fragile hooks may be occasionally snapped off by the run of a vigorous fish of moderate size, therefore it is advisable to have a supply of larger hooks, ready fixed on strong snoods, to be used when it is found that the shore is frequented by larger fishes than those generally caught close to land.

Fig. 27.—Method of attaching Snood to Eyed Hook

When fishing with a rod and line from rocks, or from piers, the foundations of which are covered with large weeds, the bait will frequently be carried by currents among the weeds and snapped off when endeavours are made to release the hook. This will especially be the case when the hook is a few feet below the lead, as we have already suggested it should be. To reduce the frequency of such mishaps, it will be a good plan to weight the gut below the lead by means of a few split shot. In fact, in sheltered places, where the water is not disturbed, these shot may take the place of the lead, but little weight being necessary for rod fishing in such localities.

The amateur sea angler is often in great doubt as to the best bait to use; and, believing that a certain kind of bait is absolutely necessary for his work in some particular spot, is often at a loss to obtain it. This bait difficulty is evidently a prevailing one among amateur sea fishers, if one may judge from the frequent questions asked as to the best or proper bait to use, and from the very common ‘Can you oblige me with a little bait?’ This latter question, we believe, is frequently the outcome of carelessness or laziness on the part of the asker. He has not the forethought, born of enthusiasm, that would lead him to procure a suitable bait, at a convenient time, previous to starting off on his angling expedition, but rather depends on the possibility of being able to beg or otherwise secure sufficient for his purpose at the time; yet there are so many good baits that are easily secured at the proper time and place that the enthusiastic angler need never be at a loss. Some of these may be collected by himself at low tide, others may be obtained from local fishermen, or from the tradesmen of the town or village.

Fig. 28.—The Lugworm

Some anglers seldom collect their own bait, either purchasing it or employing some one to collect it for them; but we are of opinion that the pleasure of a day’s fishing begins here, and especially so when the angler is of the naturalist type, for he will frequently learn more of the nature and habits of living creatures during one hour’s bait-collecting than during three or four hours’ angling. It is true that the work in question is often a bit laborious, particularly on a warm day, and that it may be frequently described as dirty and odorous; but what is that to one who is interested in his employment, and who derives pleasure in doing his own work? Fishermen often use lugworms for bait, and although these constitute one of the best baits for their own fishing, they are not so suitable for the purposes of the amateur angler, fishing with small hooks close to shore. They may be dug out of the sand when the tide is out, and are most abundant where the sand is mixed with mud. A spade should be used, and this should be thrust deep into the sand, selecting those spots where the holes or burrows of the worms most abound. Lugworms should be used whole; and being of large size, are suitable for baiting large hooks only. They may be kept alive in wet sand or sea-weed, preferably the latter for convenience, and stored till required in a wooden box.

Ragworms also afford good bait, and are particularly adapted for shore angling with small hooks. Almost all the fishes that frequent our shores take them readily, but they are not to be found in all localities. They are to be taken, though not usually in large numbers, on rocky shores where numerous stones lie among the somewhat muddy deposits of the more sheltered nooks, where they may be seen on turning over the stones. The best situation for ragworms, however, is the more or less odoriferous mud so frequently deposited in the estuaries of rivers and in landlocked harbours. Here they maybe dug out in enormous numbers with a spade, attention being directed to those spots where their burrows are most numerous. They are best stored with a little of the mud in a shallow wooden box provided with a sliding, perforated lid.

Fig. 29.—The Ragworm

Failing a supply of the marine worms just mentioned, the common earthworm may be used as a substitute, but it is decidedly less attractive to the fishes; and the same may be said of gentles—the larvæ or grubs of flies. The latter may be bred in large numbers by simply placing a piece of liver in the soil with only a small portion exposed. If this is done in the summer time, hundreds of eggs will soon be deposited on it, and in about a week or so it will be found to be a living mass of fat white grubs, perhaps more useful to the fresh-water angler than to his marine counterpart.

Among the so-called shell fish of the class mollusca, mussels, limpets, cockles, and whelks are all largely used for bait. The last of these are too large for our purpose, but form a splendid bait for deep-sea fishing, while the other three, and especially the mussels, are well suited for shore work. Mussels, in fact, provide one of the best possible baits for almost all kinds of shore fishing, the only drawback being the excessive softness of their bodies, which enables them to be easily torn from the hook. When small hooks are used, mussels of a small size may be used whole, or the larger ones may be divided into portions of suitable size; and in any case it will be found a good plan to tie the bait to the hook with a short piece of cotton thread.

Fig. 30.—Digging for Bait

Mussels are not easily opened without injury, and consequently some anglers give them a short immersion in hot water, to kill the animal and thus cause the shell to gape. As far as our own experience goes, the value of the bait is not deteriorated by this treatment, though some are of opinion that it is not so attractive after scalding. Mussels are opened, when alive, much in the same way as oysters, but the valves of the shell fit together so closely that it seems at first almost impossible to insert a knife between them. This, however, can be done with ease if one valve is first made to slide a little way over the other by pressing it with the thumb. This being accomplished, the two valves should not be separated by the mere force of the knife, for this would tear the animal within, and render it more or less unfit for its purpose; but first direct the edge of the knife towards the adductor muscle, by means of which the animal pulls its valves so firmly together, and then cut through this close to the inner surface of the upper valve. This valve can then be lifted without injury to the soft parts, and the whole animal removed from the other valve by cutting through the same muscle close to it.

Fig. 31.—Method of Opening a Mussel

Between the two lobes of the mantle—the soft covering on both sides of the animal that previously lined the shell—will be seen a brown, fleshy, tongue-like body. This is the ‘foot’ of the mussel. The point of the hook should first be run through this, and then from side to side through the mantle, and finally through the adductor muscle previously described. If this is carefully done, there will be little fear of the bait becoming detached unless it is subjected to rough usage, and still less if it is tied round the shank of the hook by means of a short piece of cotton thread.

It is probably superfluous to mention to the reader the fact that mussels are to be found on almost every rocky coast, where they may be seen attached to the rocks by means of a bunch of silky fibres called the byssus; and that, failing this, they are to be obtained from almost every fisherman and fish-dealer; if, however, these molluscs are not to be obtained, cockles may be used as a substitute, though it will probably be found that they are appreciably inferior, except when fishing for dabs and plaice on sandy shores, in which case they are highly satisfactory. Cockles abound on most sandy coasts, where they live a little below the surface; and are usually obtained by means of an ordinary garden rake. Sometimes we meet with them in large numbers in the estuaries of rivers, where they lie buried in the banks of mixed sand and mud that are left exposed at low tide.

Limpets are extensively used for bait in some places, especially by amateur anglers; and often with good results. They should always be removed from the rocks without injury, and this is no easy matter to those who do not know how to deal with them. If taken completely by surprise, one sharp, but light tap on the side of the conical shell will successfully detach them from their hold; or they may be raised by means of the blade of a strong pocket-knife that has been thrust beneath the cone.

For our work small limpets will prove far more satisfactory than large ones, and these may be used whole; but if the limpets are too large for the hooks employed, the soft, upper part of the body only need be used.

It is not an easy matter to remove fresh limpets from their shells without destroying this soft portion of the animal, but if placed for a minute or so in hot water they come out quite easily, and are apparently none the less attractive as bait. Some fishermen on the Cornish coast always collect the largest limpets for bait, remove them from their shells by means of hot water, and arrange them on the rocks to become partly dry. When required for bait, the soft parts only are used, but these, having been more or less hardened by the drying process, hold much better on the hook than when fresh.

And now, after mentioning the fact that land snails are occasionally used, though, we believe, with no very considerable success, for sea fishing, we will note a few baits derived from the higher head-footed molluscs—the squid, cuttle-fish, &c. There are several species of these peculiar molluscs, but the common squid and the common cuttle of our seas, and especially the former, is highly prized as bait. It may be obtained from fishermen, who frequently haul it in their nets; but if supplied alive and fresh from the sea it must be handled very cautiously, otherwise it may discharge the contents of its ink-bag over one with the most unpleasant results. It is certainly best used while fresh, though some suspend it until dry, and then store it for future use, in which case it will require soaking in water when required. The thin tentacles or arms are very convenient for baiting small hooks, though other parts of the body, cut into narrow strips, will serve the purpose of the angler equally well.

Of the crustaceans, shrimps and prawns, and various species of crabs are used as bait. Shrimps and prawns are used whole for catching flat-fish, but small pieces are better when fishing for smelt and other small species of fish that swim close to shore. Little pieces of the flesh of the crab are also well adapted for baiting hooks of small size, and will prove very attractive to almost all kinds of fish. Small crabs, however, may be used whole, but are of little use except when soft—that is, just after the shedding of their shells, and before the new skin has had time to harden. Such crabs may be found under stones and in other hiding-places at low tide, for at such times they keep well secluded from their numerous enemies by whom they are greedily devoured while in this helpless and unprotected condition.

The hermit-crab, which selects the empty shell of a whelk or winkle for its home, is probably well known to our readers. The protection afforded by such a home is absolutely necessary to its existence, since its abdomen has no other covering than a soft, membranous skin. This soft abdomen is frequently used as a bait with great success, as well as the flesh of the larger claws.

If the shell from which the hermit-crab is taken be broken, a worm, something of the nature of the common ragworm, will almost always be found, and this also is very serviceable as bait.

In addition to all the baits previously named there are several other good ones, many of which are to be obtained almost everywhere. Among these may be mentioned strips cut from the mackerel, herring, or pilchard, preferably with a portion of the silvery skin attached; also thin strips of tripe. Sand-eels, which may be dug out of the sand near the water’s edge, are very useful, and may be cut into pieces for baiting small hooks. Further, a large number of artificial baits are employed in various kinds of sea fishing, but as these are not essential for the work we have in hand we do not propose describing them in detail.

Now let us suppose that we are about to try our luck at sea angling, on some rocky coast, such as that of Devon and Cornwall, our object being to determine, as far as possible, what species of fishes frequent the immediate neighbourhood of the shore. And this is not all; for, when fishing with rod and line on such a coast, it frequently happens that we land some species of crab that has been attracted to our bait. The ordinary angler would regard such crab as an intruder, and, we are sorry to say, would often consider it his duty to crush the unfortunate crustacean beneath his foot. But it is far different with the naturalist. He favourably regards all creatures from which something may be learnt, and is as anxious, as a rule, to gather information concerning the habitats of one class as of another. In fact, we may go still further, and combine crab fishing with ordinary angling, both in one and the same expedition, by letting a small crab-pot down into deep water among the rocks, and allowing it to remain while the angling is proceeding.

We select a spot where there are several feet of water close to a perpendicular rock, varied and broken by numerous holes and crevices, in which various species of fishes and crustaceans habitually hide.

Such a situation is an ideal one for a young naturalist, for not only does he obtain the greatest variety of species here, but the takings will surely include some of those remarkably interesting rock-dwelling fishes that differ from our ordinary food fishes in so many points of structure, all of which, however, display some interesting adaptation to the habits and habitats of the species concerned.

Our apparatus consists of nothing more than rod and line, one or two small leads, a supply of hooks on gut snoods, a box of bait, and a waterproof bag in which to pack the specimens we desire to preserve.

We first determine the depth of the water by means of a lead on the end of the line, and then tie the hook on the end with a small lead a few feet above it, and fish in such a manner that the hook is just on the bottom, or, if the bottom is covered with weeds, the hook should be kept just clear of fouling them.

The peculiar rock fishes so common on such a coast as this on which we are engaged need special treatment at the hands of the angler. They hide in their holes, watching for the unwary creatures on which they feed, and, pouncing upon them suddenly, rush back to their snug little nooks in which they can secure themselves firmly by means of the sharp, hard spines with which their bodies are furnished. When these fishes seize the bait offered them—and they are not at all fastidious in the choice of their viands—they should be hooked and pulled up with one vigorous sweep of the rod, or they will dart into their homes, from which it is almost impossible to dislodge them.

Fig. 32.—Fishing from the Rocks

In addition to these, there will be various other species that require gentler treatment, and may be hooked and landed much in the same manner as fresh-water fishes, since they are free swimmers, usually keeping well clear of the rocks and weeds.

If the day is calm, and the water clear, the sea angler will often be able to watch various fishes as they swim, and to bring the bait gently within their reach; and here we find the advantage of the rod as compared with the hand line. Sometimes quite a shoal of small fishes may be seen sporting near the surface, and, as a rule, there will be no difficulty in obtaining one for identification and study. These are generally best secured by means of small hooks, with but very little bait, and will often bite freely at the tiniest fragment of worm on an almost naked hook.

After the water has been searched at all depths, it will be well to allow the bait to rest quite on the bottom, even at the risk of losing a hook or two in the weeds and rocks. This may enable one to take some fresh species of fish or to secure a crustacean or other creature that is not often found between the tide-marks. Care should be always taken, however, to keep the hook well clear of the weeds that grow on the sides of the rock, and sway to and fro with every movement of the restless waters.

Angling from piers may be pursued much in the same manner as described above in those places where the bottom is rocky, but since the chances of hooking large fish are greater here than close to shore, it is necessary to be provided with stronger tackle and larger hooks. If, however, the bottom is sandy, the rod tackle may be modified by placing the lead at the bottom, and arranging two or three hooks above it, about one or two feet apart, the lowest one being near the lead. With such an arrangement the line may be cast some distance out, but for angling close to the pier itself there is, perhaps, nothing better than the single-hook arrangement suggested above, for with this one may fish on the bottom and at all depths without any alteration in the tackle being necessary.

If, however, the rod line is to be cast as suggested above, or if a hand line is to be similarly used, the following hints may be useful as regards the arrangement of hooks and lead.

The line itself may be of twisted silk or hemp, terminated with about a yard of strong gut. The lead, preferably of a conical or pear-shaped form, should be placed at the extreme end, and its weight regulated according to the necessities of the occasion. A few ounces of lead are quite sufficient where there are no strong currents, but it is well to be supplied with larger sizes, to be substituted if circumstances require it. Two hooks will be ample. One of these should be only a few inches from the lead, and the other about eighteen or twenty inches higher. The whole arrangement, known as a Paternoster, is represented in fig. 33, in which the method of fixing the lead and the hook links is also illustrated.

Fig. 33.—The Paternoster

Fig. 33.—The Paternoster

It will be seen that a swivel has been introduced in connection with the bottom hook, the object being to show the manner in which this useful piece of tackle is fitted. It must not be supposed, however, that swivels are always necessary. It is often useful to insert a swivel on the line itself, above the Paternoster, when it is of twisted material, in order to prevent it from kinking; but its use is more frequently serviceable on the hook links, especially when fishing where the currents are strong. When the bait used is one that presents two flat surfaces to the water, as would be the case with a strip of mackerel, a strong current will set it spinning round and round, thus causing the hook link to kink if it has not been fitted with a swivel, and the same effect is often produced by the spinning of a fish on the hook.

The employment of a suitable ground bait will often make a wonderful difference in the angler’s haul. It frequently attracts large numbers, keeping them near at hand for some considerable time, and apparently sharpens their appetite. It may be often observed, too, that a fish will bite freely at the angler’s bait when in the neighbourhood of the ground bait, while the former is viewed with suspicion in the absence of the latter.

When fishing on the bottom only, the ground bait should be weighted if it is of such a nature that it does not sink readily or if it is liable to be carried away by currents; but it will often be found more convenient to secure it on the end of a string, tied up in a muslin bag if necessary, so that it may be adjusted to any desired depth.

Among the attractive viands suitable for this purpose we may mention mussels, crushed crabs, pounded liver, the guts of any oily fish, and the offal of almost any animal.

Along the east coast, and in some of the sandy bays of Devon and Cornwall, fishing from the beach is practised, but we can hardly recommend this as of much value to the amateur whose object is to obtain as great a variety as possible of fishes for study. Some good food fishes are often caught by this means, but the methods employed are often very primitive, and would lack all interest to those who love good sport.

On the east coast a long line, fitted with many hooks, is slung out as far as possible by means of a pole, and the home end either held in the hand of the fisher or fastened to the top of a flexible stick driven into the sand. The latter plan becomes necessary when more than one line is owned by the same individual, and he is made aware of the bite of a large fish—and a large fish only, since the hooks are placed beyond a heavy lead—by the bending of the stick.

The naturalist, however, is as much interested in the small fish as the large ones, and, even for beach fishing, a rod and line, fitted with one or two hooks only, and a lead no heavier than is absolutely essential, will be preferable. A little practice will of course be necessary in order that one may become expert in the casting of the rod line, but with large rings on the rod, and a reel without a check, or a check that can be thrown off when desired, the necessary proficiency in casting ought to be acquired without much difficulty.

In some of the sandy bays of the south-west, long lines with a heavy lead at both ends and baited hooks at short intervals throughout the whole length, are placed on the sand at low tide close to the water’s edge, and left unwatched until the next tide is out. As far as our observations go this primitive mode of fishing is usually anything but successful, the receding of the tide generally revealing a long row of clean hooks, with, perhaps, one or two dead or half-dead fish; and it is probable that most of the bait is devoured by crabs and other crustaceans before the water becomes sufficiently deep to allow the desired fishes to reach it.

There is one other method of fishing on which we may make a few remarks, although it hardly comes under the heading of shore fishing. We refer to a method of catching surface fishes from a moving boat, which method is known as whiffing. The line is weighted with a lead which must be regulated according to the speed of the boat. If the boat is an ordinary rowing-boat, kept going at only a moderate speed, a few ounces of lead will be sufficient, but a whiffing line trailing behind a sailing boat travelling in a good breeze will require a pound or two of lead to keep the bait only a little below the surface.

Beyond the lead we have three or four yards of gimp or strong gut, at the end of which is a single hook fitted with a spinner, or baited with some attractive natural or artificial bait. Whatever be the bait used, there will certainly be more or less spinning caused by the resistance offered by the water, hence it will be necessary to have a swivel beyond the lead.

When whiffing near the shore, care must be taken to avoid outlying rocks that approach the surface of the water, or a sudden snapping of the line will give you an unwelcome warning of their existence. Further, we should note that the fishes which are to be caught when whiffing do not always swim at the same depth, thus it will be advisable to fish at different distances from the surface by varying either the weight of the lead or the speed of the boat.

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CHAPTER IV
THE MARINE AQUARIUM

We have already advised our readers to take home their specimens alive for the purpose of studying their growth and habits. Now, although there may be some difficulties in the way of keeping marine animals and plants alive for any considerable time, yet we are inclined to emphasise the importance of this matter, knowing that the pleasure and instruction that may be obtained from even a moderately successful attempt to carry this out will far more than compensate for the amount of trouble entailed. There are very many marine objects that are exceedingly pretty and also very instructive, even when studied apart from the life with which they were associated in the sea. Thus, a well-preserved sea-weed may retain much of its original beauty of form and colour, the shells of numerous molluscs and crustaceans exhibit a most interesting variety of features well worthy of study, and a number of the soft-bodied animals may be preserved in such a manner as to closely resemble their living forms. This being the case, we can hardly say anything to discourage those who gather sea-side objects merely for the purpose of making a collection of pretty and interesting things to be observed and admired. Such objects must necessarily afford much pleasure and instruction, and the time spent in the collection and preparation will certainly cause the collector to stray to the haunts of the living things, where he is certain to acquire, though it may be to a great extent unconsciously, a certain amount of knowledge concerning their habits and mode of life. Moreover, sea-side collecting is one of the most healthy and invigorating of all out-door occupations, and for this reason alone should be encouraged.

Yet it must be observed that he whose sea-side occupation is merely that of a collector, and whose work at home is simply the mounting and arranging of the objects obtained, can hardly be considered a naturalist. Natural history is a living study, and its devotee is one who delights in observing the growth and development of living things, watching their habits, and noting their wonderful adaptation to their environments; and it is to encourage such observation that we so strongly recommend the young collector to keep his creatures alive as far as it is possible to do so.

The first thing to settle, then, is the nature of the vessel or vessels that are to serve the purpose of aquaria for the work of the young naturalist.

As long as the outdoor work is in progress temporary aquaria will be very useful as a means by which the objects collected may be sorted and stored until a final selection is made for the permanent tank. These temporary aquaria may consist of jars or earthenware pans of any kind, each containing a few small tufts of weed, preferably attached to pieces of rock, and a layer of sand or gravel from the beach.

As such temporary aquaria will, as a rule, be within a convenient distance from the sea-side where the collecting is being done, there will be, we presume, no great difficulty in the way of obtaining the frequent changes of water necessary to keep the animals and plants in a healthy condition, so that we need do no more now than urge the importance of avoiding overcrowding, and of renewing the water frequently for the purpose of supplying the air required for the respiration of the inmates.

When it is desired to isolate small species in such a manner that their movements may be conveniently observed, glass jars answer well; but whatever be the form or size of the vessels used, care must be taken to avoid excess of both light and heat. They should be kept in a cool place, quite out of the way of direct sunshine, and the glass vessels used should be provided with a movable casing of brown paper to exclude all light except that which penetrates from above.

Even temporary aquaria, used merely for the purpose suggested above, should be carefully watched, for a single day’s neglect will sometimes result in the loss of several valuable captives. A dead animal should be removed as soon as it is discovered to avoid the unpleasant results arising from the putrefaction of its body. The appearance of a scum or film on the surface of the water should always be regarded with suspicion. Such a scum should be removed with the aid of absorbent paper, since it tends to prevent the absorption of oxygen from the air; and, should the water be tainted in the slightest degree, it should be changed at once, or, if this is not practicable, air should be driven into it for some time by means of a syringe with a very fine nozzle. Such precautions, however, are not so urgently needed when the aquarium contains crustaceans only, for the majority of these creatures suffer less than others in the tainted sea water, some even being apparently quite as comfortable in this as in a supply fresh from the sea. Sea-weeds exhibiting the slightest tendency to decay must be removed at once; and, as regards the feeding of the animals, one must be careful to introduce only as much food as is required for immediate use, so that there be no excess of dead organic matter left to putrefy. Some of the marine animals obtained from our shores feed entirely on the minute and invisible organisms that are always present in the sea water, and others subsist principally on certain of the weeds. Many, however, of a more predaceous disposition, capture and devour living prey, while some, and more especially the crustaceans, are partial to carrion. If, therefore, the observer desires to study the ways in which the various creatures secure and devour their food, he should introduce into his aquaria live marine worms and other small animals, and also small pieces of fish or flesh.

We will now pass on to the more serious undertaking of the construction and management of a permanent salt-water aquarium.

The first point to decide is, perhaps, the size of the proposed vessel, and this will in many cases be determined partly by a consideration of the space at one’s disposal, and of the apartment it is intended to occupy. If it is to be placed in a drawing-room or other ordinary apartment of a dwelling-house, preference should be given to a window facing the north in order to avoid the direct rays of the sun, but perhaps no situation is more suitable than a cool conservatory in the shady part of a garden; and in either case a strong table or other support should be provided, of a form and size adapted to those of the aquarium to be constructed.

Various materials may be used in the construction of such an indoor aquarium, and we shall deal with two or three different types, so that the reader may make his selection according to his fancy, or to his mechanical ability, if he intends that it shall be of his own construction.

We will begin with an aquarium constructed entirely of a mixture of cement and fine sand, this being the most inexpensive and certainly the easiest to make; and although it may not be regarded as the most ornamental—but opinions will differ on this point—yet it has the decided advantage of being the nearest approach to the natural rock pool. Though somewhat heavy and cumbersome, even when empty, the amount of material used in its construction may be varied according to the taste and convenience of the maker. Further, this form of aquarium is one that will readily admit of structural alterations at any future period. It may be deepened at any time; lateral additions or extensions may be made, or a portion may at any time be shut off for the purpose of isolating certain of the animals procured.

Fig. 34.—Section of an Aquarium constructed with a mixture of Cement and Sand

The first thing to do is to prepare a flat, strong slab of hard wood or stone, the exact shape and size of the desired artificial pool, and then cover this, if of wood, with a mixture of fine sand and cement, mixed to a convenient consistency with water, to the depth of about one inch. The banks or walls of the pool must then be built up on all sides, and this is best done by the gradual addition of soft pellets of cement, applied in such a manner as to produce an irregular surface. Unless the walls of the aquarium be very thick and massive the cement will soon show a tendency to fall from its place as the height increases, but this may be avoided by doing the work in instalments, allowing each portion to set before further additions are made to the structure.

Since some marine animals like to occupy snug and shady niches in deep water while others prefer full exposure to the light in shallows, arrangements should be made for all by varying the depth of the bed, and providing several little tunnels and caverns. This may be accomplished either by working the cement itself into suitable form, or by means of piled stones obtained from the sea beach; and if the latter plan is adopted, the stones should not be obtained until the aquarium is quite ready for its living contents; for then a selection of stones and rock fragments with weeds, anemones, sponges, and other fixed forms of life attached to them, may be made. The natural appearance of a rock pool is thus more nearly approached, and in a shorter time than if the sedentary life were required to develop on an artificial ground.

Objection may be raised to the form of aquarium just described on the ground that no life within it is visible except when viewed from above. But is not this also the case with a rock pool on the sea shore? And has any admirer of nature ever been heard to complain of the beauties of such a pool because he was unable to look at them through the sides? Further, it may be urged that the inmates of our aquarium will be living under more natural conditions than those of the more popular glass-sided aquaria, because they receive light from above only.

Fig. 35.—Cement Aquarium with a Glass Plate in Front

However, should the reader require a glass front to his cement tank, the matter is easily accomplished. Three sides are built up as before described. A sheet of thick glass—plate glass by preference—is then cut to the size and shape of the remaining space, and this is fixed by means of cement pressed well against its edges, both inside and outside.

Water should not be put into the tank until it is quite dry; and, if one side is made of glass, not until the cement surrounding the edge of the glass has been liberally painted with marine glue, hot pitch, or some other suitable waterproof material.

If any pipes are required in connection with the water supply of the aquarium, according to either of the suggestions in a later portion of this chapter, such pipes may be fixed in their proper places as the cement sides are being built up.

The next type of aquarium we have to describe is of low cost as far as the materials are concerned, and one that may be made by any one who has had a little experience in woodwork; and although the tank itself is of a simple rectangular form, yet it may be made to look very pretty with a suitable adjustment of rocks and weeds.

It consists of a rectangular box, the bottom, ends, and back of which are of hard wood, firmly dovetailed together, and the front of plate glass let into grooves in the bottom and ends. All the joints and grooves are caulked with marine glue, but no paint should be used in the interior.

This form of tank may be vastly improved by the substitution of slabs of slate for the wood, though, of course, this change entails a much greater expenditure of both time and cash; but supposing the work to be well done, the result is everything that could be desired as far as strength and durability are concerned.

Fig. 36.—Aquarium of Wood with Glass Front

In either of the rectangular tanks just described glass may be used for two sides instead of one only; and since this is not a matter of very great importance, the choice may well be left to the fancy of the one who constructs it.

Some prefer an aquarium with glass on all sides, and where this is the case the framework may be made of angle zinc with all the joints strongly soldered. Such an aquarium may be made in the form of any regular polygon, for it is no more difficult to construct one of six or eight sides than of four. It is more difficult, however, to make such an aquarium perfectly watertight, for the glass, instead of being in grooves, has to be securely fastened to the metal frame by means of a cement on one side only, and this cement has to serve the double purpose of holding the glass and keeping in the water.

Various mixtures have been suggested for this purpose, and among them the following are perfectly satisfactory:—

1.	Litharge	2 parts
	Fine sand	2 ”
	Plaster of Paris	2 ”
	Powdered resin	1 part

Mix into a very thick paste with boiled linseed oil and a little driers.

2.	Red lead	3 parts
	Fine sand	3 ”
	Powdered resin	1 part

Mix with boiled linseed oil as above.

Both these cements should be applied very liberally, and the aquarium then allowed to remain quite undisturbed for at least two weeks before any water is introduced.

Fig. 37.—Hexagonal Aquarium constructed of Angle Zinc, with Glass Sides

When ready for the water, the bottom of the aquarium should be covered with a moderately thick layer of fine sand from the sea shore, and stones then piled in such a manner as to form little tunnels and caves to serve as hiding-places for those creatures that prefer to be under cover. As to the selection of stones, we have already suggested that some may have weeds rooted to them, and that pieces of rock with anemones, sponges, and other forms of life attached may be chipped off. Further, on many of our rocky coasts we may find, near low-water mark, a number of stones covered with a layer of vegetable growth, amongst which many small animals live, often more or less concealed by their protective colouring. Some of these stones placed on the bed of the salt-water aquarium would add greatly to the natural appearance, as well as give greater variety to the living objects. Shells bearing the calcareous, snakelike tubes of the common serpula ([p. 121]), preferably with the living animals enclosed, will also enhance the general appearance and interest of the aquarium.

In making preparations previous to the introduction of animal life, due regard should be paid to the peculiar requirements of the creatures it is intended to obtain. We have already referred to the advisability of arranging the bed of the tank in such a manner that the water may vary considerably in depth, so that both deep and shallow water may be found by the animals as required, and to the provision of dark holes for crustaceans and other creatures that shun the light. Very fine sand should be provided for shrimps, prawns, and other animals that like to lie on it; and this sand must be deep in places if it is intended to introduce any of the burrowing molluscs and marine worms.

The water used may be taken from the sea or be artificially prepared. The former is certainly to be preferred whenever it can be conveniently obtained, and at the present time few will find much difficulty in securing a supply, for not only are we favoured with the means of obtaining any desired quantity by rail at a cheap rate from almost any seaport, but there are companies in various ports who undertake the supply of sea water to any part of the kingdom. If the water is to be conveyed from the coast without the aid of the regular dealers in this commodity, great care must be taken to see that the barrel or other receptacle used for the purpose is perfectly clean. Nothing is more convenient than an ordinary beer or wine barrel, but it should be previously cleansed by filling it several times with water—not necessarily sea water—and allowing each refill to remain in it some time before emptying. This must be repeated as long as the water shows the slightest colouration after standing for some time in the barrel.

Should any difficulty arise in the way of getting the salt water direct from the sea, it may be made artificially by dissolving ‘sea salt’ in the proper proportion of fresh water, or even by purchasing the different salts contained in the sea separately, and then adding them to fresh water in proportionate quantities.

The composition of sea water is as follows:—

Water	96·47	per cent.
Sodium chloride	2·70	”
Magnesium chloride	·36	”
Magnesium sulphate (Epsom salts)	·23	”
Calcium sulphate	·14	”
Potassium chloride	·07	”
Traces of other substances	·03	”
	100·00

and it will be seen from this table that artificial sea water may be made by adding about three and a half pounds of sea salt, obtained from the sea by the simple process of evaporation, to every ninety-six and a half pounds of fresh water used. In making it there may be some difficulty in determining the weight of the large volume of water required to fill an aquarium of moderate dimensions, but this will probably disappear if it be remembered that one gallon of water weighs just ten pounds, and, therefore, one pint weighs twenty ounces.

If the sea salt cannot be readily obtained, the following mixture may be made, the different salts being purchased separately:—

Water	96½	lbs.
Sodium chloride (common salt)	43¼	ozs.
Magnesium chloride	5¾	”
Epsom salts	3¾	”
Powdered gypsum (calcium sulphate)	2¼	”

Although in this mixture the substances contained in the sea in very small quantities have been entirely omitted, yet it will answer its purpose apparently as well as the artificial sea water prepared from the true sea salt, and may therefore be used whenever neither sea salt nor the natural sea water is procurable.

Assuming, now, that the aquarium has been filled with sea water, it remains to introduce the animal and vegetable life for which it is intended; and here it will be necessary to say something with regard to the amount of life that may be safely installed, and the main conditions that determine the proportion in which the animal and vegetable life should be present in order to insure the greatest success.

Concerning the first of these we must caution the reader against the common error of overcrowding the aquarium with animals. It must be remembered that almost all marine animals obtain the oxygen gas required for purposes of respiration from the air dissolved in the water. Now, atmospheric air is only very slightly soluble in water, and hence we can never have an abundant supply in the water of an aquarium at any one time. If a number of animals be placed in any ordinary indoor aquarium, they very soon use up the dissolved oxygen; and, if no means have been taken to replace the loss, the animals die, and their dead bodies soon begin to putrefy and saturate the water with the poisonous products of decomposition.

It is probably well known to the reader that a large proportion of the oxygen absorbed by the respiratory organs of animals is converted by combination of carbon into carbonic acid gas within their bodies, and that this gas is given back into the water where it dissolves, thus taking the place of the oxygen used in its formation.

If, then, an aquarium of any kind is to be a success, some means must be taken to keep the water constantly supplied with fresh oxygen quite as rapidly as it is consumed, and this can be done satisfactorily by the introduction of a proportionate quantity of suitable living weeds, providing there is not too much animal life present.

The majority of living plants require carbonic acid gas as a food, and, under the influence of light, decompose this gas, liberating the oxygen it contained. This is true of many of our common sea-weeds, and thus it is possible to establish in a salt-water aquarium such a balance of animal and vegetable life that the water is maintained in its normal condition, the carbonic acid gas being absorbed by the plants as fast as it is excreted by animals, and oxygen supplied by the plants as rapidly as it is consumed by the animals.

This condition, however, is more difficult to obtain in a salt-water aquarium than in one containing fresh-water life, partly because, generally speaking, the sea-weeds do not supply oxygen to the water as rapidly as do the plants of our ponds and streams, and partly because of the difficulties attending the successful growth of sea-weeds in artificial aquaria. Thus it is usually necessary to adopt some means of mechanically aërating the water; but, for the present, we shall consider the sea-weeds only, leaving the mechanical methods of aërating the water for a later portion of this chapter.

In the first place, let us advise the amateur to confine his attention to the smaller species of weeds that are commonly found in small and shallow rock pools, for the successful growth of the larger purple and olive weeds will probably be beyond his power, even though his tank be one of considerable capacity. The best plan is that we have already suggested—namely, to chip off small pieces of rock with tufts of weed attached, and to fix them amongst the rockery of the aquarium, being careful to place those that grew in shallow water with full exposure to the light, and those which occupied sheltered and shady places in the rock pool, respectively, in similar situations in the artificial pool.

For the purposes of aëration we have to rely principally on the bright green weeds, and preference should be given to any of these that exhibit, in their natural habitat, a multitude of minute air-bubbles on the surface of their fronds, for the bubbles consist principally of oxygen that is being liberated by the plant, and denote that the species in question are those that are most valuable for maintaining the desired condition of the water in an aquarium.

Any small sea-weed may be tried at first, but experience will soon show that some are much more easily kept alive than others. In this experimental stage, however, a constant watch should be maintained for the purpose of detecting signs of decay in the marine garden. A plant should always be removed as soon as it presents any change from the natural colour, or exhibits the smallest amount of slimy growths on the surface, for decomposing plants, as well as decaying animals, will soon convert an aquarium into a vessel of putrid and poisonous water.

It seems almost unnecessary to name a selection of sea-weeds for small aquaria, seeing that our rock pools produce so many extremely beautiful species, most of which may be successfully kept alive in a well-managed tank; but the common Sea Grass (Enteromorpha compressa), and the Sea Lettuce (Ulva latissima), also known locally as the Green Laver or Sloke, are particularly useful for the aëration of the water; while the Common Coralline (Corallina officinalis), the Dulse (Schizymenia edulis), the Peacock’s tail (Padina pavonia), the Irish or Carrageen Moss (Chondrus crispus), Callithamnion, Griffithsia setacea, Plocamium plumosium, Rhodymenia palmata, Rhodophyllis bifida, and Ceramium rubrum are all beautiful plants that ought to give no trouble to the aquarium-keeper.

It is not advisable to introduce animal life into the aquarium immediately it is filled, on account of the possibility of the water being contaminated by contact with the cement that has been used to make it water-tight. It is safer to allow the first water to stand for a few weeks, the weeds and all other objects being in situ, and the necessary means employed for perfect aëration during this interval, and then, immediately before the animals are placed in their new home, to syphon off the whole of the water, and refill with a fresh supply.

In the selection of animals due regard should be paid to two important points—first, the danger of overcrowding, and, secondly, the destructive habits of some of the more predaceous species.

No more than two or three animals should, as a rule, be reckoned for each gallon of water; and the proportion of animals should be even less than this when any of them are of considerable size.

As regards the destructive species, these are intended to include both those that are voracious vegetable feeders and also those whose habit it is to kill and prey on other creatures.

It must be understood that the weeds are to serve two distinct purposes:—They are to supply at least some of the oxygen required for the respiration of the animal inmates, and also to serve as food for them. Some marine fishes and molluscs feed on the fronds of the weeds, and among these the common periwinkle may be mentioned as one of the most voracious. If many such animals are housed in the aquarium, it will be necessary to replace at intervals those species of weeds that suffer most from their ravages. The zoospores thrown off by the weeds, particularly in the autumn, are also valuable as food for some of the animals.

Notwithstanding the destructive character of the periwinkle just referred to, it has one redeeming feature, for it is certainly useful in the aquarium as a scavenger, as it greedily devours the low forms of vegetable life that cover the glass and rocks, thus helping to keep them clean; and the same is true of the common limpet and other creeping molluscs. Some of these are even more to be valued on account of their partiality for decaying vegetable matter, by devouring which they reduce the amount of the products of decomposition passing into the water.

Other details concerning the selection of animal and vegetable life for the indoor aquarium must be left to the discretion and experience of the keeper, for it is impossible by written instructions and advice to cover all the various sources of loss and trouble that may from time to time arise. If, however, the general hints for the management of the marine aquarium here given be faithfully followed, there ought to be no further losses than must accrue from the injudicious selection of animal species, and these will decrease as experience has been acquired respecting the habits of the creatures introduced.

We must now pass on to matters pertaining to the maintenance of the healthy condition of an aquarium which, we will suppose, has been established with due regard to scientific principles. Under this head we shall consider, (1) the aëration of the water, (2) the repair of loss due to evaporation, and (3) the regulation of light and temperature.

It has already been shown that the marine aquarium can hardly be maintained in a satisfactory condition as regards its air supply by leaving the aëration of the water entirely to the action of plant life; and herein this form of aquarium differs from that employed for the animal and vegetable life derived from ponds and streams. Fresh-water weeds develop and multiply with such rapidity, and are such ready generators of oxygen gas that it is a very easy matter to establish a fresh-water aquarium that will remain in good condition for years with but little attention; it is therefore important that we should point out the difference in treatment necessary to those of our readers who are already acquainted with the comparative ease with which the fresh-water aquarium may be kept in good order, lest they expect the same self-aërating condition in the marine tank.

It is never a good plan to leave the renovation of the water of the aquarium until there are visible signs within that something is going wrong. It is true that an unsatisfactory condition of the water, revealed by a slight taint in the odour, or a general turbidity, or the formation of a slight scum on the surface, may sometimes be rectified by the prompt application of some method of artificial aëration, but the aim of the aquarium-keeper should be not the rectification of unsatisfactory conditions, but the establishment of such a method of aëration that the unsatisfactory condition becomes an impossibility. We do not wish to discourage anyone who has the slightest desire to start a marine aquarium. Our aim is to point out any difficulties that lie in the way in order that the aquarium may be a success; and thus, having stated that the difficulties attending it are somewhat greater than those connected with the management of a fresh-water aquarium, we should like to add that these practically disappear when one is prepared to devote a short time at regular intervals in order to see that the process of aëration is properly carried out.

Some recommend the occasional injection of air by a syringe as one means of aërating the water; but, although this may be all very well as a temporary purifier of the slightly tainted aquarium, it is hardly suitable as a means of maintaining a good, healthy condition. It must be remembered that oxygen gas—the gas of the atmosphere so essential to animal life—is only very slightly soluble in water. By this we mean not only that water dissolves oxygen very slowly, but also that it can never hold a large supply of the gas at any one time. This being the case, it is clear that the use of a syringe for a short time, though it discharges an enormous total volume of air into the water, will result in the actual solution of only a small quantity. No method of aëration is perfect that allows the admission of air for a short time only at comparatively long intervals; the most perfect system is that in which air is slowly but continuously passed into solution.

Since air is slightly soluble in water, it is clear that it must be continuously passing into any body of water that has its surface freely exposed to it; hence a wide and shallow aquarium is much more likely to keep in good order than one that is narrower and deeper. But, with marine aquaria, the simple absorption from the air at the surface is not in itself sufficient, as a rule, to maintain a healthy condition. Yet it will be advisable to remember this matter when constructing a tank for marine life.

One of the prettiest, and certainly one of the most effectual, methods of supplying air to an aquarium is by means of a small fountain with a very fine spray. The water need seldom be changed, but the fountain may be fed by water from the aquarium, and as the fine spray passes through the air it will absorb oxygen and carry it in solution to the tank.

The accompanying diagram illustrates the manner in which this can be accomplished. The aquarium (a) is supplied with an outlet (o) about an inch from the top by means of which the water is prevented from overflowing, and the outlet pipe leads to a vessel (v) of considerable capacity which, for the sake of convenience and appearance, may be concealed beneath the table on which the aquarium stands. Some feet above the level of the aquarium is another vessel (c), supported on a shelf, having about the same capacity as v, and supplied with a small compo pipe that passes down into the aquarium, and then, hidden as much as possible by the rockery, terminates in a very fine jet just above the level of the water in the centre. The upper vessel should also be provided at the top with a loose covering of muslin to serve as a strainer, and this should be replaced at intervals as it becomes clogged with sedimentary matter.

In order that this arrangement may give perfect satisfaction the two vessels (c and v) must each be of at least half the capacity of the aquarium itself, and the total quantity of salt water sufficient to fill the aquarium together with one of them. It should also be remembered that since the pressure of water depends not on its quantity, but on its height measured perpendicularly, it follows that the height to which the fountain will play is determined by the height of the vessel c above the level of the jet.

Fig. 38.—Method of aërating the Water of an Aquarium

a, aquarium with fountain; c, cistern to supply the fountain; o, pipe for overflow; v, vessel for overflow

Let us now suppose that the aquarium and the upper vessel have both been filled with sea water. The fine jet from the pipe plays into the air and returns with a supply of oxygen to the aquarium, while the excess above the level of o passes into the concealed vessel below the table. If the two vessels are as large as we recommend, and the jet a very fine one, the fountain may continue to play for hours before c is empty, the animals of the tank being favoured all this time with a continuous supply of air. And when the supply from above is exhausted, the contents of the bottom vessel are transferred to the top one, and at the same time so effectually strained by the layer of muslin that no sedimentary matter passes down to choke the fine jet of the fountain. One great advantage this method possesses is that the living creatures derive the benefit of a much larger quantity of water than the aquarium alone could contain; and thus, apart from the aërating effects of the fountain, the result is the same as if a much larger tank were employed.

In our next illustration (fig. 39) we give a modified arrangement based on the same principle which may commend itself by preference to some of our readers. Here the supply pipe to the fountain passes through a hole in the bottom of the aquarium instead of into the top, and the outlet pipe is bent downward within so as to form a syphon.

Those who are acquainted with the principle of the syphon will understand at once the working of such an arrangement as this. Let us suppose the vessel c to be full of water, and the fountain started, while the water in the aquarium stands no higher than the level l. The water slowly rises until the level h of the bend of the outlet tube has been reached, and during the whole of this time no water escapes through the exit. As soon, however, as the latter level has been attained, the water flows away into the lower vessel, into which it continues to run until the lower level is reached, and then the outflow ceases, not to commence again until the fountain causes the water to rise to the upper level.

Fig. 39.—Aquarium fitted with Apparatus for Periodic Outflow

From what has been said the reader will see that the total quantity of water required in this instance need not exceed the capacity of the aquarium; also that each of the vessels connected with water supply and waste should have a capacity equivalent to the volume of water contained in the aquarium between the two levels h and l.

The alternate rising and falling of the water produced in the manner just described represents in miniature the flow and ebb of the tides, but perhaps this is in itself of no great advantage in the aquarium except from the fact that it allows those creatures that prefer to be occasionally out of the water for a time a better opportunity of indulging in such a habit. And further, with regard to both the arrangements for aëration above described, it should be noted that earthenware vessels are much to be preferred to those made of metal for the holding of sea water, since the dissolved salts corrode metallic substances rather rapidly, and often produce, by their chemical action, soluble products that render the water more or less poisonous.

Other methods of aërating the water of aquaria are practised, but these, as a rule, are only practicable in the case of the large tanks of public aquaria and biological laboratories, as the mechanical appliances necessary to carry them out successfully are beyond the means of an ordinary amateur.

In such large tanks as those referred to it is common to force a fine jet of air into the water by machinery. Sometimes this air is driven downward from a jet just below the surface, and with such force that a multitude of minute bubbles penetrate to a considerable depth before they commence to rise, but in others the air is made to enter at the bottom and must therefore pass right through the water.

Of course the amateur aquarium-keeper may carry out this method of aëration with every hope of success providing he has some self-acting apparatus for the purpose, or can depend on being able himself to attend to a non-automatic arrangement at fairly regular intervals, always remembering that a single day’s neglect, especially in the case of a small tank with a proportionately large amount of animal life, may lead to a loss of valuable specimens.

We have already mentioned the use of a syringe as a means by which an aquarium may be temporarily restored to a satisfactory condition providing it has not been neglected too long, and some recommend forcing air, or, still better, pure oxygen gas, from an india-rubber bag into the water. We have used, for the same purpose, a stream of oxygen from a steel cylinder of the compressed gas with very satisfactory results; and since oxygen may be now obtained, ready compressed, at a very low price—about twopence a cubic foot—there is much to be said in favour of this method as an auxiliary in the hands of the owner of a small tank, though we hardly recommend it as a prime means of aëration to take the place of the fountain.

In any case, where a stream of air or oxygen is employed, an exceedingly fine jet should be used, in order that the expelled gas may take the form of a stream of minute bubbles; for, as previously stated, the water can absorb the gas only very slowly, so that there must necessarily be a considerable waste when the gas issues rapidly. Further, the smaller the bubbles passing through the water, the greater is the total surface of gas in contact with the liquid, the volume of the supply being the same, and hence the more effectually will the solution of the gas proceed. Again, another advantage of the fine stream of minute bubbles lies in the fact that the smaller these bubbles are the more slowly they rise to the surface of the water, and thus the longer is the time in which the gas may be absorbed during its ascent.

A fine jet, well suited to the purpose here defined, may be made very easily by holding the middle of a piece of glass tubing in a gas flame until it is very soft, and then, immediately on removing it, pulling it out rather quickly. A slight cut made with a small triangular file will then enable the operator to sever the tube at any desired point.

Yet another method of maintaining the air supply of aquaria is adopted in the case of some of the large tanks of public aquaria and biological laboratories situated close to the sea, and this consists in renewing the water at every high tide by means of pumps.

It must not be supposed that an indoor aquarium, even when well established, and supplied with the best possible system of aëration, requires no further care and attention. In the first place there is a continual loss of water by evaporation, especially in warm and dry weather, and this must be rectified occasionally. Now, when water containing salts in solution evaporates, the water passing away into the air is perfectly free from the saline matter, and thus the percentage of salt in the residue becomes higher than before. It is evident, therefore, that the loss by evaporation in a marine aquarium must be replaced by the addition of fresh water, which should either be distilled, or from the domestic supply, providing it is soft and moderately free from dissolved material.

But the question may be asked, ‘Do not the marine animals and plants utilise a certain amount of the saline matter contained in the salt water?’ The answer to this is certainly in the affirmative, for all sea-weeds require and abstract small proportions of certain salts, the nature of which varies considerably in the case of different species; and, further, all the shelled crustaceans and molluscs require the salts of lime for the development of their external coverings, and fishes for the growth of their bony skeletons. Hence the above suggestion as to the replenishment of loss by evaporation with pure water is not perfectly satisfactory. It will answer quite satisfactorily, however, providing the sea water is occasionally changed for an entirely new supply. Again, since carbonate of lime is removed from sea water more than any other salt, being such an essential constituent of both the external and internal skeletons of so many marine animals, as well as of the calcareous framework of the coralline weeds, we suggest that the aquarium may always contain a clean piece of some variety of carbonate of lime, such as chalk, limestone, or marble, which will slowly dissolve and replace that which has been absorbed.

Water is rendered denser, and consequently more buoyant, by the presence of dissolved salts; and, since the density increases with the proportion of dissolved material, we are enabled to determine the degree of salinity by finding the density of the solution. We can apply this principle to the aquarium, as a means of determining whether the water contains the correct amount of sea salt, also for testing any artificial salt water that has been prepared for the aquarium.

Probably some of our readers are acquainted with some form of hydrometer—an instrument used for finding the density of any liquid; but we will describe a simple substitute that may be of use to the owner of a marine aquarium, especially if the salt water for the same is artificially prepared. Melt a little bees-wax, and mix it with fine, clean sand. Then, remembering that the wax is lighter than water, and consequently floats, while sand is considerably heavier, and sinks, adjust the above mixture until a solid ball of it is just heavy enough to sink very slowly in sea water. Now make two such balls, and then cover one of them with a light coating of pure wax. We have now two balls, one of which will float in sea water, and the other sink, and these may be used at any time to test the density of the water in, or prepared for, the aquarium. If the water is only a little too salt, both balls will float; while, if not sufficiently rich in saline matter, both will sink.

We must conclude this chapter by making a few remarks on the important matter of the regulation of light and temperature. Direct sunlight should always be avoided, except for short and occasional intervals, not only because it is liable to raise the temperature to a higher degree than is suitable for the inmates of the aquarium, but also because an excess of light and heat tends to produce a rapid decomposition of organic matter, and a consequent putrid condition of the water, and this dangerous state is most likely to occur when both light and temperature are high at the same time.

The water should always be cold; and as it is not always easy to estimate the temperature, even approximately, by the sensation produced on immersing the fingers, it is a good plan to have a small thermometer always at hand, or placed permanently in the aquarium. In the summer time the water should be kept down to fifty-five degrees or lower, and in winter should never be allowed to cool much below forty. There may be some difficulty in maintaining a temperature sufficiently low in summer, but a small piece of ice thrown in occasionally to replace the loss due to evaporation, especially on very hot days, will help to keep it down.

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CHAPTER V
THE PRESERVATION OF MARINE OBJECTS

The sea-side naturalist, in the course of his ramblings and searchings on the coast, will certainly come across many objects, dead or alive, that he will desire to set aside for future study or identification in his leisure moments at home. Some of these will be required for temporary purposes only, while, most probably, a large proportion will be retained permanently for the establishment of a private museum, that shall serve not only as a pleasant reminder of the many enjoyable hours spent on the shore, but also as a means of reference for the study of the classification of natural objects and of their distribution and habitats.

We will first deal with those specimens that are required for temporary purposes only—those of which the collector desires to study the general characters, as well as, perhaps, something of the internal structure; but before doing so we cannot refrain from impressing on the reader the advisability of learning as much as possible of the external features and mode of growth of the different living creatures while still alive, for it must be remembered that it is impossible to preserve many of them without more or less destruction of their natural colouring and distortion of their characteristic forms.

In those cases where it is possible to keep the creatures alive for a short time only, it is a good plan to make notes of their movements and all observed changes in form, and their methods of feeding, and also to illustrate these notes by sketches drawn from life. This may seem quite an unnecessary procedure to many beginners in the study of natural objects, and may even, as far as the sketches are concerned, present difficulties that at first appear to be insurmountable; but the power to sketch from nature will surely be acquired to a greater or less degree by constant practice, and illustrated notes prepared for the purpose we suggest will undoubtedly be of great value to the student. Further, though it may often be necessary to set specimens aside in a preservative fluid until one has the leisure to examine their structure, it should always be remembered that they never improve by keeping, also that they are rarely in such good condition for dissection after saturation with the preservative as when perfectly fresh.

One of the most convenient preservatives for general use is undoubtedly methylated spirit. This is alcohol that has been adulterated in order to render it undrinkable, so that it may be sold free from duty for use in the various arts and manufactures without any danger of its being employed for the concoction of beverages. It may be used just as purchased—that is, in its strongest condition—for many purposes, but in this state it has a powerful affinity for water, and will rapidly abstract water from animal and vegetable objects, causing the softer ones to become hard, shrunken, and shrivelled, often to such an extent that they are almost beyond recognition.

By diluting the spirit, however, we satisfy to a great extent its affinity for water, and thus prevent, or, at least, reduce the action just mentioned. A mixture of equal quantities of spirit and water is quite strong enough. Unfortunately the common methylated spirit of the shops produces a fine white precipitate, that gives the whole mass a milky appearance, when it is diluted. This is due to the presence of mineral naphtha, which is added in a certain fixed proportion in accordance with the Government regulations. But it is possible, by special application, to obtain the ‘non-mineralised’ or ‘ordinary’ methylated spirit of former years, though not in small quantities, and this liquid dissolves in water without the formation of a precipitate. It should be noted, however, that the use of the spirit as a preservative is in no way interfered with by the presence of the mineral naphtha, the only disadvantage of this impurity lying in the fact that the milkiness consequent on dilution prevents the objects in a specimen jar from being observed without removal.

We have just referred to the hardening action of strong spirit as a disadvantage, and so it is when it is required to preserve soft structures with as little as possible of change in general form and appearance; but there are times when it becomes necessary to harden these soft structures in order that sections may be made for the purpose of examining internal structure with or without the aid of the microscope, and for such purposes strong spirit is one of the best hardening agents that can be employed.

Formaldehyde is another very good preservative. It is a colourless liquid, and should be considerably diluted for use, a two per cent. solution being quite strong enough for all ordinary purposes. It possesses some distinct advantages as compared with spirit. In the first place, it does not destroy the natural colours of objects to the extent that spirit does; and, although a hardening agent as well as a preservative, it does not harden soft structures by the extraction of the water they contain, and therefore does not cause them to become shrivelled or otherwise distorted. It will also occur to the reader that, since a small bulk of formaline represents a large volume of the diluted preservative, it is very conveniently stored, and a very small bottle of it taken for outdoor work may, on dilution with water, be made to yield all that is required for the preservation of the takings of a successful day, or even of a longer period. Formaldehyde is usually sold in solution of about forty per cent. strength, and for the preparation of a two per cent. solution it will be found convenient to provide a glass measure graduated either into cubic centimetres or fluid ounces and drams. One hundred volumes of the original solution contain forty of pure formaldehyde, and if water be added to make this up to two thousand volumes, a two per cent. solution is obtained. Thus, one hundred cubic centimetres of the original solution is sufficient to prepare two litres (three and a half pints) of suitable preservative.

A very good preservative liquid may be made by dissolving two ounces of common salt, one ounce of alum, and two or three grains of corrosive sublimate (a deadly poison) in one quart of water, and then, after allowing all sedimentary matter to settle to the bottom, decanting off the clear solution. This mixture is known as Goadby’s fluid, and is well adapted for the preservation of both animal and vegetable structures. It does not cause any undue contraction of soft tissues, and, as a rule, does not destroy the natural colours of the objects kept in it.

Glycerine is valuable as a preservative for both animal and vegetable objects, and especially for the soft-bodied marine animals that form such a large percentage of the fauna of our shores. It maintains the tissues in a soft condition, and preserves the natural tints as well as any liquid.

An inexpensive preservative may also be made by dissolving chloride of zinc—about one ounce to the pint of water. This is considered by some to be one of the best fluids for keeping animal structures in good condition.

Now, although the different fluids here mentioned are described in connection with the temporary preservation of natural objects, it must be remembered that they are equally adapted for the permanent preservation of the animals and plants that are to figure in the museum of the sea-side naturalist; and, although some marine objects may be preserved in a dry state in a manner to be hereafter described, yet there are many species of animals, and also some plants, that can be satisfactorily preserved only by immersion in a suitable fluid.

This method may be applied to all soft-bodied animals, such as anemones, jelly-fishes, marine worms, shell-less molluscs (sea slugs, cephalopods, &c.), the soft parts of shelled molluscs, fishes, &c.; and most sponges retain their natural appearance much better in a preservative fluid than in a dry condition. Many sea-weeds also, which are practically destroyed by the most careful drying process, are most perfectly preserved in fluid.

But the puzzled amateur will probably be inclined to ask: ‘Which is the best preservative liquid for this or that specimen?’ No satisfactory general rule can be given in answer to such a question, and a great deal will have to be determined by his own experiments and observations. Whenever he has two or three specimens of the same object, as many different fluids should be employed, and the results compared and noted. In this way a very great deal of useful information will be obtained and by the best possible means. However, it may be mentioned that all the fluids alluded to above may be safely used for almost every animal or vegetable specimen with the following reservations: strong spirit should not be employed for any very soft animal, nor should it be used for delicate green plants, since it will dissolve out the green colouring matter (chlorophyll), leaving them white or almost colourless. Further, the greatest care should be exercised in dealing with sea anemones and jelly-fishes. If spirit is used for preserving these creatures, it should be very dilute, at least at first, but may with advantage be increased in strength afterwards, though this should be done gradually.

Whatever be the preservative used, it is sure to be more or less charged with sedimentary and coloured matter extracted from the object immersed in it; hence, if the specimen concerned is to form part of a museum collection, it will be necessary to transfer it to a fresh solution after a time, and a second, and even further changes may be necessary before the object ceases to discolour the fluid or render it turbid.

Considerable difficulty will sometimes be found in the attempts to preserve a soft-bodied animal in its natural attitude. Thus, when a sea anemone is removed from its native element, it generally withdraws its tentacles, and, contracting the upper part of its cylindrical body, entirely conceals these appendages, together with the mouth they surround; and a mollusc similarly treated will generally pull itself together within its shell, leaving little or no trace of the living body inhabiting the lifeless case. Then, if these animals are transferred to any fluid other than sea water, or placed anywhere under unnatural conditions, they usually remain in their closed or unexpanded form. Thus, almost every attempt to kill them for preservation deprives them of just the characteristics they should retain as museum specimens.

Some such animals may be dealt with satisfactorily as follows: Transfer them to a vessel of fresh sea water, and leave them perfectly undisturbed until they assume the desired form or attitude. Then add a solution of corrosive sublimate very gradually—a drop or two at intervals of some minutes. In this way the bodies of anemones may be obtained ready for preservation with expanded tentacles, tube-secreting worms with their heads and slender processes protruding from their limy or sandy cases, molluscs with their ‘feet’ or their mantles and gills protruding from their shells, and barnacles with their plume-like appendages projecting beyond the opening of their conical shells.

The specimens thus prepared may be placed at first in very dilute spirit, and then, after a time, finally stored in a stronger solution of spirit in water; or they may be transferred to one of the other preservative solutions previously mentioned.

All specimens permanently preserved in fluid for a museum should be placed in jars, bottles, or tubes of suitable size, each vessel containing, as a rule, only one. Where expense is no object, stoppered jars made expressly for biological and anatomical specimens may be used for all but the smallest objects; or, failing this, ordinary wide-mouthed bottles of white glass, fitted with good corks or glass stoppers.

For very small specimens nothing is more suitable than glass tubes, but it must be remembered that wherever corks are used, even if they are of the best quality procurable, it will be necessary to look over the specimens occasionally to see if the preserving fluid has disappeared to any extent either by leakage or evaporation; for such loss is always liable to occur, although it may be very slow, and especially when methylated spirit is the liquid employed.

Fig. 40.—Jars for preserving Anatomical and Biological Specimens

The writer has preserved many hundreds of small marine and other objects in glass tubes of dilute spirit that have been hermetically sealed, thus rendering the slightest loss absolutely impossible, while the perfect exclusion of air prevents the development of fungoid growths that sometimes make their appearance in imperfectly preserved specimens. The making and closing of such tubes, though a more or less difficult operation at first to those who have had no previous experience in glass-working, become exceedingly simple after a little practice; and believing it probable that many of our readers would like to try their hand at this most perfect method of preserving and protecting small objects, we will give a description of the manner in which it is done.

The apparatus and materials required for this work are:—Lengths of ‘soft’ glass tubing, varying from about one quarter to a little over half an inch in internal diameter; a supply of diluted spirit—about half spirit and half water; a Herapath blowpipe, preferably with foot-bellows; and a small triangular file.

The glass tubing may be cut into convenient lengths by giving a single sharp stroke with the file, and then pulling it apart with, at the same time, a slight bending from the cut made.

Fig. 41.—Showing the different stages in the making of a small Specimen Tube

Cut a piece of tubing about eight or nine inches long, heat it in the blowpipe flame, turning it round and round all the time, until it is quite soft, then remove it from the flame and immediately pull it out slowly until the diameter in the middle is reduced to about a sixteenth of an inch (fig. 41, 2). Make a slight scratch with the file at the narrowest part, and divide the tube at this point (fig. 41, 3). Now heat one of these pieces of tubing as before just at the point where the diameter of the drawn part begins to decrease; and, when very soft, pull it out rather quickly while it is still in the flame. The part pulled now becomes completely separated, and the tube is closed, but pointed. Continue to heat the closed end, directing the flame to the point rather than to the sides, until the melted glass forms a rather thick and flattened end; and then, immediately on removing it from the flame, blow gently into the open end until the melted glass is nicely rounded like the bottom of a test-tube (fig. 41, 4). When the tube is cold, the specimen that it is to contain, and which has already been stored for a time in dilute spirit, is dropped into it. The tube is now heated about an inch above the top of the specimen, drawn out as shown in fig. 41, 5, and again allowed to cool. When cold, the fresh spirit is poured into the open end of the tube, but the middle part is so narrow that the spirit will not run down freely. If, however, suction be applied to the open end, air from the bottom will bubble through the spirit, and then, on the cessation of the suction, the spirit will pass down to take the place of the air that was withdrawn. This may be repeated if necessary to entirely cover the specimen with the fluid. Any excess of spirit is then thrown from the upper part of the tube, and the latter cut off. Nothing is now left but to close the tube hermetically. This is done by heating the lower part of the narrow neck, and then drawing it out in the flame, taking great care that the tube is withdrawn from the flame the moment it is closed. The tube must also be kept in an upright position until it has cooled. The appearance of the finished tube is shown in fig. 41, 6.

Fig. 42.—Small Specimen Tube mounted on a Card

All preserved specimens should have a label attached on which is written the name of the specimen, the class and order to which it belongs, the locality in which it was found, together with any brief remarks that the owner desires to remember concerning its habits &c.

The bottles or tubes that are too small to have a label attached to them in the ordinary way may be mounted on a card, as represented in fig. 42, and the desired particulars then written on the card.

When soft or delicate specimens are preserved in a bottle of fluid they frequently require some kind of support to keep them in proper form and to display them better for observation. Perhaps the best way to support them is to fasten them to a very thin plate of mica of suitable size by means of a needle and very fine thread. The mica is so transparent that it is invisible in the fluid, and the few stitches are also hardly perceptible, thus making it appear as if the specimen floats freely in the fluid.

We will now pass on to consider those objects of the shore that are usually preserved in a dry condition, commencing with