To the best of my recollection my own investigations were chiefly carried on standing stork fashion upon a tussock, surrounded by an inky opacity, which threatened to draw the investigator downwards with a clutch, more tenacious and formidable than that of any sundew. To the faithful Irish botanist the poverty of the Flora of Ireland as compared with that of Great Britain has always been a serious humiliation. In this respect these Droseraceæ form an exception. Of the few British species all, I think, are to be found upon the bogs of the West of Ireland, the largest of them—appropriately called anglica—being much commoner in Ireland than elsewhere in these islands.
A very slight acquaintance with their habits could hardly fail, I think, to convince even the most sceptical that their roots are mainly employed as anchors, and water-pipes, while for a supply of that nitrogen which every plant requires they are chiefly, if not exclusively, dependent upon insects. Of these the two lesser species would appear to content themselves with the smallest of Diptera and Lepidoptera, whereas anglica will occasionally tackle larger prey, and I have myself seen it with a good-sized moth (a noctua) attached to and nearly covering the entire disk, the long tentacle-like hairs being closely inflected over the victim, whose struggles are soon put an end to, once the sticky secretion exuding from the hairs closes above the trachea. When the leaf re-opens nearly the whole of the insect (be it fly, moth or beetle) will be found to have disappeared, even the wings being reduced to a few glittering fragments. No animal substance in fact comes amiss; fragments of bone, hide, meat-fibrine, and even, according to one authority, tooth enamel, softening, and in time dissolving under the powerful solvent secreted by the glands. Whether the Droseraceæ have the power of attracting their prey, or must wait until chance sends it within their clutches, seems undecided. In the case of a little Portuguese relative, one Drosophylum lusitanicum (growing, unlike other members of the family, upon dry hills in the neighbourhood of Oporto) such a power appears undoubtedly to exist, the people of the neighbourhood using it as a flycatcher, and hanging it upon their walls for that express purpose.
This meat-eating habit or instinct (whichever we may agree to call it) is shared to a greater or less extent by all the Droseraceæ, such as the Venus’s fly-trap, the Byblis gigantea of Australia, and a small but curious aquatic cousin, known to botanists by the formidable name of Aldrovanda vesiculosa, whose tiny leaves have the power of shutting vice-like over every unfortunate insect which approaches them, and which thus finds itself enclosed in a floating prison. If eminently characteristic of them, this carnivorousness is by no means confined however to the sundews, and their allies. If anything the Pinguiculas, for instance, rather exceed them in voracity. Few plants are at once so beautiful, and so interesting from the problems to which their distribution gives rise, as is the great Irish butterwort—Pinguicula grandiflora. Unknown to England and Scotland; unknown to the whole north of Europe; unknown even to the rest of Ireland; its viscid green rosettes may be seen on most of the lowlands of Kerry, and upon many of the bogs of south Cork. For nine months of the year that is all that there is to see. In June a flower-stalk rises out of the centre of the rosette, crowned with a pendulous bell of the most pellucid, the most ethereal shade of violet. Happily for the susceptibilities of the investigator this is not the flesh-eating portion of the plant, that office being strictly confined to the leaves. Stooping down and examining these leaves we find that, whereas some are flat, others are slightly dog-eared along the edges. If further we unroll a few of the dog-ears we discover the remains, not of one alone, but often of a dozen unfortunate flies and midges, in all stages of assimilation; some already half-digested, others still alive, and struggling to escape from their glutinous prison. If further we place a fragment of bone, of meat, or indeed of any nitrogenous substance, upon the edge of one of the fully expanded leaves, we shall find that little by little the leaf begins curling upwards, until the two edges approach, and then join. Finally the morsel is lost to sight, becoming entirely immersed in its bath of secretion, where it remains until all its nutritive parts are absorbed.
Viscous as the whole surface of the leaf is, it does not seem as if this process of digestion was carried on with the same rapidity in the centre as at the sides, and, as there are in this case no long hairs to act as locomotive organs, it often happens that one may see flies and other small insects lying partially dried up and useless in the centre of the leaf. In one respect this viscidity appears at first sight to be inconvenient, the entire surface of the leaf being often covered with twigs, leaves, particles of boggy fibre, and such-like matters, which the plant has apparently no power of getting rid of. In the end this may prove however to be an advantage rather than otherwise, since it has been ascertained that the Pinguiculas feed, not alone on animal, but also on vegetable substances; the extreme stickiness of the leaves causes them moreover to act as a chevaux-de-frise, thus hindering small but industrious ants from making their way up the flower-stalks to the corolla.
Yet another little group of bog-plants, namely, the Utricularias, or bladderworts, are meat eaters. In their case the fly-catching apparatus is situated, not in the leaves, but in certain small attached air-bladders, which are constructed almost exactly upon the principle of an eel-trap, and which, if opened, may generally be found to contain flies. Thus we see how discovery may be anticipated, and how one of man’s most boasted attributes—that of the Destroyer—may be wrested from him by a miserable little green bog-weed! Before the first Celtic hunter flung spear at wolf or stag; before the Firbolgs, or the Tuatha-da-Daanans—cunning workers and craftsmen—had set up any gins or traps in the wilderness; before the first monk or abbot had arranged ingeniously devised weirs, wherein the salmon—seemingly by miracle—rang a bell to announce its own arrival; before any of these things had been done, or thought of, little Utricularia minor and little Utricularia intermedia had set up their own primitive green eel-traps in the yet unvisited wastes of Iar-Connaught.
May 5, 1900
FEW events are more gratifying than to find oneself taken more seriously by other people than by oneself, and I am pleased therefore to discover that our palpably artificial little pond has been taken possession of by a colony of frogs, which must have travelled some distance to make its acquaintance, frog-haunted ponds or even ditches being by no means abundant on these dry hillsides of ours.
I have never myself met more than one species of frog in these islands. Professor Bell, however, speaks of another, Rana Scotica, which he held to be distinct, but the difference seems to be mainly one of size. It is extremely difficult to persuade anyone who has noticed the multitudes of frogs which swarm in Ireland that they were only introduced there artificially, and as lately as the beginning of last century. Such, nevertheless, is the fact, and the date of the event is, moreover, a tolerably fixed one. It was a Dr. Gunthers, or Guithers, who, in the year 1705, turned out a handful of spawn into a ditch near Trinity College. For some years the frogs appear to have contented themselves with the neighbourhood of that University, but sixteen years later, in 1721, they were found forty miles away, from which point they seem to have rapidly extended themselves over the whole island. Incidentally the fact is confirmed by a great, if hardly a zoological authority, namely, Dean Swift. In his Considerations about Maintaining the Poor, which appeared in the year 1726, in the course of thundering against certain fire offices, which had the impertinence to be English, he declares that “their marks upon our houses spread faster and further than a colony of frogs.” The portent, therefore, it is plain, had reached his ears.
Coincidences are attractive things, and it is satisfactory to discover that as regards earlier times we are again able to fortify our mere lay zoology upon the authority of an eminent ecclesiastic. This time it was St. Donatus, bishop of Etruria, who, writing in the ninth century, assured the world, upon his episcopal authority, that no frogs or toads existed, or, moreover, could exist in Ireland. Three centuries later Giraldus Cambrensis tells us, however, that in his time a frog was taken alive near Waterford, and brought into court, Robert de la Poer being then warden. “Whereat,” he says, “Duvenold, King of Ossory, a man of sense amongst his people, beat upon his head, and spake thus: ‘That reptile is the bearer of doleful news to Ireland.’ ” Giraldus is careful, however, to assure us that “no man will venture to suppose that this reptile was ever born in Ireland, for the mud there does not, as in other countries, contain the germs from which frogs are bred”; indeed, in another part of the Topographia Hibernica we learn that frogs, toads, and snakes, if accidentally brought to Ireland, on being cast ashore, immediately “turning on their backs, do burst and die.” This statement is corroborated by a still more illustrious authority, that of the Venerable Bede, whom Giraldus quotes as follows: “No reptile is found there” (in Ireland), “neither can any serpent live in it, for, though oft carried there out of Britain, so soon as the ship draws near the land, and the scent of the air from off the shore reaches them, immediately they die.” So efficacious was the very dust of Ireland that on “gardens or other places in foreign lands being sprinkled with it, immediately all venomous reptiles are driven away.” So, too, with fragments of the skins and bones of animals born and bred in Ireland; indeed, parings from Irish manuscripts, and scraps of the leather with which Irish books were bound, were amongst the accredited cures for snakebite until well on in the Middle Ages. Of his own personal experience Giraldus relates to us how, upon a certain occasion, a thong of Irish leather was, in his presence, drawn round a toad, and that, “coming to the thong, the animal fell backward as if stunned. It then tried the opposite side of the circle, but, meeting the thong all round, it shrank from it as if it were pestiferous. At last, digging a hole with its feet in the centre of the circle, it disappeared in the presence of much people.”
Our frogs and toads are not likely at present to become an affliction to us. Should they ever do so I must certainly send for some Irish leather, or, failing that, for a pinch of Irish dust, and try its effect upon them. An influence that has been vouched for by such a variety of authorities ought to retain something of its ancient potency. Scientific experiments in any case are always interesting!