Intelligence in Plants and Animals / Being a New Edition of the Author's Privately Issued "Soul and Immortality."

by Thomas G. Gentry

Of the exact method used by the fish in binding the nest together we are indebted to Prof. Ryder. The male fish spins from a pore or pores a compound thread, using his body to insinuate himself through the interstices through which he carries the thread. The thread is spun fitfully, not continuously. He will go round and round the nest perhaps a dozen times, when he will rest awhile and begin anew. Its shape is somewhat conical before completion. The thread is wound round and round the nest in a horizontal direction, and when freshly spun is found to consist of six or eight very thin transparent fibres, which have alternated tapering ends where they are broken off. Very soon after the thread is spun, particles of dirt adhere to it, and render it difficult to interpret its character. The nest measures one-half of an inch in height, and three-eighths in diameter.

The time occupied in collecting materials and constructing the nest is about four hours, and when all is ready the male starts out to seek a female, and, having found her, conducts her with many polite attentions to the prepared home. The eggs being deposited, the male establishes himself as a guardian of the precious treasures, not even suffering the female to approach it again. Every fish that comes near, no matter how large, is furiously assailed. He gives battle valiantly, striking at their eyes and seizing their fins in his mouth. His sharp dorsal and ventral spines are very effective weapons in his defence. Constant watchfulness upon the part of the male is needed, for, if he go away for only a few moments, the sticklebacks and other fish lurking in the vicinity rush in and devour the eggs in an instant. A whole month he is occupied in providing for the safety of his offspring. About the tenth day he employs himself in tearing down the nest and carrying the material to some little distance. The fry may now be observed in motion. And these the male continually nurses, suffering no encroachment, and if the young brood show a tendency to stray beyond bounds, they are driven back within their precincts, until they are strong enough to provide for their own living, when both old and young disappear together.

But nothing in the lives of all these little nest-builders is more interesting than the intelligence they display and the facility with which they adapt themselves to circumstances. They seem to be able to grasp almost instantly the conditions of the environment, and to employ a wise discrimination in suiting them to their wants. Hardly two nests are alike. Marked differences in details of structure, configuration and surroundings are apparent, which prove that these creatures are controlled by reason, rather than instinct, in the elaboration of their homes. That they have some means of communicating their desires to each other cannot be doubted. When the male has laid hold of a stem, a pebble or a stick that completely baffles all effort at removal, his mate seems summoned to his assistance, and the united strength of the pair accomplishes the object to be gained. There is ever noticeable in whatever the sexes undertake some concert of action which would put to shame the boasted intelligence of man himself. The Sun-fishes, as has been said, nest in companies. When the combined effort of two individuals is unable to expel an invader, the entire community, as by a single mighty impulse, rises up against the foe. There is evidence of some form of society, even though simple in its organization, where individual members league themselves together for mutual protection and defence. Other examples might be cited to give the reader a common-sense estimate of the comparatively high order of intelligence that characterizes the actions of many of our fishes.

SLIPPERY AS AN EEL.

Eels are found in almost all warm and temperate countries, and grow to a very great size in tropical regions. They are impatient of cold, and hence do not exist in the extreme northern and southern parts of the world. In many islands of the Pacific Ocean they are held in considerable estimation, being preserved in ponds and fed by hand, but in many civilized communities a strong prejudice prevails against them, probably from their similarity to snakes, which prevents even a hungry man from caring to eat such wholesome and nutritious food.

Not one of our river fishes is so mysterious as the Eel, and although much is now known that was involved in obscurity, yet there is still much to learn of its habits, especially the manner of its reproduction. Difference of locality, it is likely, may influence the Eel and cause a difference of habit, an opinion which seems warranted from the various and perplexing accounts that have been given of its customs by numerous practical observers.

During the hot, still and sunny days of June they are chiefly seen on top of the water, wherever masses of aquatic weeds may be found, either in the calm enjoyment of a sun-bath, or for the purpose of feeding upon the myriads of gnats, moths and flies that seek the plants for rest or food, and which by unavoidably damping their wings become easy prey to their ambushed enemies. At night, similar retreats are affected for like purposes. Floating masses of detached weeds that the eddying stream has wound and kept in one place are sought in warm, stilly weather, but in blowing, cooler or rainy weather they forsake such places for the still, deep ditches. If a flush of water comes, and a little, shallow stream, running from or into the main river, becomes fuller than usual, there they resort in vast numbers, evidently pleased with the delicious change, only to remain as long as its freshness continues.

Like many other fishes, Eels are very tenacious of life, and can live a long time when removed from the water, owing to a simple and beautiful modification of structure, which permits them to retain a sufficient amount of moisture to keep the gills damp and in a condition to perform their natural functions. They have been seen crawling over considerable distances, somewhat snake-like in their movements, evidently either in pursuit of water, their own dwelling-place being nearly dried, or in search of some running stream in whose waters they may reach the sea after the customary manner of their race. Multitudes of Eels, both old and young, some of the latter scarcely six inches in length, have been seen crawling up the banks of a creek, apparently without any purpose, and over the smooth surface of a projecting rock, with all the ease of a fly moving over a ceiling. So active were the little ones as to defy, unless the hand was moved with extreme rapidity, their capture. Vast numbers of these little Eels are in the habit of proceeding up the rivers in the spring-time. In some places in England they are called Elvers. They are caught in immense quantities, and scalded and pressed into masses termed Eel- or Elver-cake. When dressed these little Eels afford a luxurious repast. Towards the latter part of summer these fishes migrate towards the sea, being capable of living in fresh or salt water with equal ease, the mouths of rivers constituting favorite localities. Even in our seaport towns and marine watering-places the common river Eel is caught by those who are angling in the sea for fish.

Various modes of capturing Eels are adopted by man. Bobbing, or clodding as it is sometimes called, is a very common and successful method, consisting in bunching a number of earthworms upon a worsted string, and lowering it near the place where the fishes are supposed to be feeding. So eagerly do the voracious fish seize the bait, and so fiercely do they bite, that they are pulled out of the water before they have time to collect their thoughts and disengage their teeth from the string. Night-lines, which are laid in the evening and taken up in the morning, are another plan. But the most successful method is by spearing. The spear used for the purpose is not unlike the conventional trident of Neptune, except that the prongs are four in number, flattened, slightly barbed on each edge, and spread rather widely from their junction with the shaft. This is pushed at random into the muddy banks where the Eels love to lie, and when one is caught, its long snake-like body is wedged in between the jagged prongs and lifted into the boat before it is able to extricate itself. Almost any kind of food that it can master, whether aquatic or terrestrial, is eaten to satisfy the creature’s most voracious appetite. Even mice and rats fall victims to its hunger, and an Eel is recorded to have been found floating dead on the water, having been choked to death by a rat which it had essayed to swallow, but which proved too large a morsel for its throat.

So remarkable is the tenacity of life which this fish possesses, that after the creature has been cut up into lengths, each separate piece will move as if alive, and at the touch of a pin’s point will curve itself as though it felt the injury. When all irritability has ceased, the portions will flounce vigorously about if placed in boiling water, and even after its influence has ceased will, upon the addition of salt, jump about as vigorously as before. There can be no real sensation, let it be understood, as the spinal cord has been severed and all connection with the brain, which is the seat of sensation, has been cut off.