Nature who has with the utmost care allotted to every species of animals its peculiar place of residence and its peculiar kind of food, has also with equal wisdom furnished every individual with the means of rendering such habitation the most commodious, and of procuring such food with the greatest ease. Numberless expedients, numberless stratagems has she instructed even the minutest insects in, for the ensnaring and over-powering those animals which she has destined to be his prey. Of these we shall in the course of this work relate many, of which, however, there are few more curious, and at the same time more simple than that of the little animal which now falls under our consideration.
The formica-leo, or lion-pismire, is a very small insect, not much bigger than a large emmet, which, however, notwithstanding its name, bears no resemblance to the pismire class, either in its figure or disposition. On the contrary, as the laborious ant ranges about every where with the greatest industry to find its food in the summer-time, and lay it up in storehouses for the winter; the animal we are speaking of keeps itself ever confined to a single spot, waiting with a most amazing degree of patience and perseverance for the supply of the present moment, as chance shall throw it in its way; nay, even when that chance has so far favoured him as to bring some devoted victim towards his cell, he instead of advancing forwards to lay hold on it, constantly retires from it, as if he seemed to make it a point that the destruction of it should be entirely its own act, or unavoidable misfortune.
The form of the lion-pismire is that represented at Fig. I. and II. in the plate annexed to this work, of which the first represents the back, and the other the belly, although both about four times as big as life. The body of it is of an annular texture, by which means the tail is rendered extremely pliable and apt for the use which we shall hereafter describe. It has six legs, placed as those of most insects are in the thorax. Its head is small and flat, and from the forepart of it two pretty long horns shoot out, and between them a pair of serrated or saw-like forcipes, wherewith it destroys and tears to pieces those creatures which are unfortunate enough to fall within its reach. The horns are about the sixth part of an inch in length, and bend like hooks in the extremity. Towards their insertion appear two small eyes very black and lively, and which are extremely serviceable to the creature, for he starts from the smallest objects he discovers. Other animals are furnished with wings, or feet at least, to render them expeditious in the pursuit of their prey. But this creature seems to make use of his legs for little more purpose than to bear him backwards from his prey, which as we have before observed must come to him. He is, however, provided with means of causing it to fall into the ambuscade he prepares for it. This is the only resource he has for subsistence, the only piece of skill that he is master of. That power, however, which has provided for every one whatever may be needful, has rendered this one knowledge sufficient for all his purposes whilst in his terrestrial state; for this creature, as we shall farther relate, undergoes some of those metamorphoses which we have before given an account of. His method of obtaining food is then as follows:
The place which he always chuses as fittest for the scene of action is a bed of dry sand, at the foot of a wall, or under some shelter where no rain can come at it, either to disconcert his work, or prevent the effect of his operations; which could by no means answer their intended purpose, were they to be attempted either in a solid soil, or in a moist sand, neither of which would be tractable to his tools, or become serviceable to the completion of his design.
He begins to work then, by bending the hinder part of his body which tapers into a point, and then plunging it like a plough-share into the sand, which he throws up in his rear with a backward motion of his body; and thus by repeating his efforts, and taking several rounds, he at last traces out a circular furrow, whose diameter always equals the depth which he intends to sink it. Near the edge of the first furrow he opens a second, and then a third, and so on to a great number, every one of which is smaller then the preceding one; sinking himself from time to time deeper and deeper in the sand, which he throws wide with his horns, still casting it up behind him with his rail as with a spade, and by the repeated strokes of his head whirling it out of the circle till he has compleatly formed his cell, which is a cavity in the form of an inverted cone, or the inside of a funnel.
This cell is larger or smaller in proportion to the growth, and consequently to the size of the animal; but in a full grown one, is sometimes upwards of two inches in diameter and as much in depth.
When this loose and unstable fabrick is thus finished, he forms his ambuscade in the center of it, concealing himself in such a manner under the sand, that his horns form an exact circle round the central termination, or apex of the cone. In this situation he remains entirely motionless watching for his prey, which is composed of small insects of many kinds, more especially the female ant, who being unprovided with wings, like the generality of insects, is less able to escape when once me falls into the snare. Other animals, however, are far from being safe from the dexterity of this skillful hunter. Fatal is the moment in which any one is so indiscreet as to venture near the edge of this precipice, which descending in a steep slope, and that formed of a light loose sand, immediately gives way, and hurries it down instantly to the center. But lest its own weight should not be sufficient to prevent its recovering a first false step, no sooner does our ambuscader perceive by the fall of some few grains of sand that a prize is near, than by shrinking back he removes the lower sand, and undermining the more extreme parts obliges the bank to break and roll down, bringing down with it, and at the same time overwhelming whatsoever happens to be near its verge.
It sometimes, however happens, that the insect thus entrapped being endowed with peculiar agility, or provided with wings, is able to rise above this first envelopement. In this case the lion-pismire defeats its efforts by whirling a large quantity of sand into the air by means of his tail above the height of the rising animal. This falling again in what to so tender a creature as a gnat, fly, or emmet, is equal to a dreadful shower of stones, the unfortunate insect beat down, overwhelmed by the tempest that pours down from every quarter, and hurried away by the instability of the sand which rolls from under his feet, falls between the serrated forcipes of his enemy, who plunging them into his body, drags it under the land, and there triumphantly feasts on his thus devoted victim.
This great end being brought about, and our voracious animal thus sated with an ample meal sucked from the juices of his prey, his next care is to remove the carcase, lest the appearance of a dead body should alarm others, and give notice of the fatal and treacherous nature of this seemingly inoffensive cavern. He therefore extends his horns, and with a sudden spring tosses the light exuvium of the slain to at least half a foot beyond the borders of his trench. And in case his habitation should in the course of one of these exploits be any way disconcerted or filled up, if the aperture becomes too large for the depth, or the declivity loses its proper slope, he instantly sets himself to work and repairs the whole, rounding, deepening, and clearing the cavity with a most amazing expertness; which done, he again conceals himself in the sand, and waits in an apparent state of inactivity for whatever shall fall next into his snare.
In the doing this his patience and perseverance are so great, and nature has provided him with such abilities for abstinence, that he sometimes passes whole weeks, nay months without motion, and what is still more surprizing without food itself.
The lion-pismire, hid at the bottom of his trench, and whirling the sand on an ant to prevent its regaining the bank, is represented at Fig. III.
The lion-pismire, however, as I have observed before, does not pass his whole life under the form we have here described. He is to become a fly; but before he can undergo so great and extraordinary a metamorphosis, it is necessary that he should pass through a period of temporary death, for which state he prepares in the following manner, building to himself a secure and convenient tomb, wherein he lies decently inurned till the appointed moment when he is to arise from his inactive state, and become the inhabitant of another element.
When the time comes for this resignation of his first life, he troubles himself no further about the order and form of his trench, but falls to work in the sand, striking out a great number of irregular tracks in it, with an eagerness that appears as if it was designed to throw him into a sweat. Be this as it will, it is certain that his body becomes at this time covered over with a viscous moisture, which as he rolls himself about in the sand, wherein he plunges himself in every direction, fixes and unites all the grains he touches. With these sandy particles and the dried glew that consolidates them, he forms a crust which encompasses his whole body like a little ball of five or six twelfths of an inch diameter (Vid. fig. IV.) Within this ball, however, he reserves to himself a sufficient space to move about; and as a bare wall of sand would be too harsh and cold for him to remain happily in, he lines it throughout with a kind of silk tapestry of his own weaving, composed of threads formed from his bowels, of a beautiful pearl colour, and infinitely surpassing in fineness that of the silk-worm. Yet whilst it is thus commodiously and elegantly furnished within-side, the exterior still retains the same rugged and undesirable appearance, by which it escapes the notice of birds and other animals of prey, who might perhaps be tempted by a more alluring outside.
In this situation he lives secluded from the world, for six weeks or two months, and sometimes more: at the end of which period nature having performed her secret work, he divests himself of his horns, paws, and skin, his spoils sink to the bottom of the ball, like a suit of cast-off cloathing, and his figure is then that of the nympha, represented greatly magnified, and in two different directions at Fig. V. and VI. when tearing away his tapestry and bursting his rocky enclosure, he comes out a perfect animal of the dragon-fly kind, furnished with four large filmy wings, with which he quits the obscurity of his former state; becomes divested of his barbarity and subtile inclinations, as well as of his cumbersome weight, and in short appears entirely a new animal, as is shewn in Fig. VII.
The animal before us, however, is not the only example of this kind of subtilty in the insect world. There has heen discovered another creature, which from the resemblance it has to the lion-pismire in the method of digging a trench for intrapping its prey, has been distinguished by the authors who have described it by the name of the vermis-leo, or lion-worm. But as what we have said of the formica-leo, will equally describe the method of this creatures procuring its food, we shall not trouble our readers with any farther detail concerning it; but content ourselves with only presenting them a drawing of it at Fig. VIII. in the annexed copperplate, in which a and b represent the worm in its first state, c shews the nympha, or second period of its life, and d the form of the fly, or last transformation.