THE CABINET OF NATURAL HISTORY 



the walls, gain a sufficient footing to effect their escape. 

 When the pitfall is intended to be small, it only thrusts its 

 body backwards into the sand as far as it can, throwing out 

 at intervals the particles which fall in upon it till it is ren- 

 dered of the requisite depth. 



By shutting up one of these grubs in a box with loose 

 sand, it has been repeatedly observed constructing its trap of 

 various dimensions, from one to three inches in diameter, 

 according to circumstances. When it intends to make one 

 of considerable diameter, it proceeds as methodically as the 

 most skilful architect or engineer amongst ourselves. It first 

 examines the nature of the soil, whether it be sufficiently 

 dry and fine for its purpose, and if so, it begins by tracing 

 out a circle, where the mouth of its funnel-trap is intended 

 to be. Having thus marked the limits of its pit, it proceeds 

 to scoop out the interior. Getting within the circle, and 

 using one of its legs as a shovel, it places therewith a load 

 of sand on the flat part of its head, and it throws the whole 

 with a jerk, some inches beyond the circle. It is worthy of 

 remark, that it only uses one leg in this operation — the one, 

 namely, which is nearest the centre of the circle. Were it 

 to employ the others in digging away the sand, it would 

 encroach upon the regularity of its plan. Working with 

 great industry and adroitness in the manner we have just 

 described, it quickly makes the round of its circle, and as it 

 works backwards it soon arrives at the point where it had 

 commenced. Instead, however, of proceeding from this 

 point in the same direction as before, it wheels about and 

 works around in the contrary direction, and in this way it 

 avoids throwing all the fatigue of the labour on one leg, 

 alternating them every round oi the circle. 



Were there nothing to scoop out but sand or loose earth, 

 the little engineer would have only to repeat the operations 

 we have described, till it had completed the whole. But 

 it frequently happens in the course of its labours, some- 

 times even when they are near a close, that it will meet 

 with a stone of some size which would, if suffered to re- 

 main, injure materially the perfection of its trap. But such 

 an obstacle as this does not prevent the insect from proceed- 

 ing: on the contrarjr, it redoubles its assiduity to remove the 

 obstruction, as M. Bonnet repeatedly witnessed. If the 

 stone be small, it can manage to jerk it out in the 

 same manner as the sand; but when it is two or three 

 times larger and heavier than its own body, it must have 

 recourse to other means of i-emoval. The larger stone 

 it usually leaves till the last, and when it has removed all 

 the sand which it intends, it then proceeds to try what 

 it can do with the less manageable obstacles. For this 

 purpose, it crawls backwards to the place where a stone 

 may be, and thrusting its tail under it, is at great pains to 

 get it properly balanced on its back, by an alternate 



motion of the rings composing its body. When it has 

 succeeded in adjusting the stone, it crawls up the side of 

 the pit with great care and deposits its burden on the 

 outside of the circle. Should the stone happen to be 

 round, the balance can be kept only with the greatest 

 difficulty, as it has to travel with its load upon a slope of 

 loosQ sand which is ready to give way at every step; and 

 often when the insect has carried it to the very brink, it 

 rolls off its back and tumbles down to the bottom of the 

 pit. This accident, so far from discouraging the Ant-Lion, 

 only stimulates it to more persevering efforts. Bonnet 

 observed it renew these attempts to dislodge a stone, five 

 or six times. It is only when it finds it utterly impossible 

 to succeed, that it abandons the design and commences 

 another pit in a fresh situation. When it succeeds in 

 getting a stone beyond the line of its circle, it is not con- 

 tented with letting it rest there ; but to prevent it from again 

 rolling in, it goes on to push it to a considerable distance. 



The pitfall, when finished, is usually about three inches 

 in diameter at the top, about two inches deep, and gradually 

 contracting into a point in the manner of a cone or funnel. 

 In the bottom of this the Ant-Lion stations itself to 

 watch for its prey. Should an ant or any other insect 

 wander within the verge of this funnel, it can scarcely fail 

 to dislodge and roll down some particles of sand, which will 

 give notice to the Ant-Lion below to be on the alert. In 

 order to secure the prey, Reaumur, Bonnet, and others 

 have observed the ingenious insect to throw up showers of 

 sand, by jerking it from its head in quick succession, till 

 the luckless ant is precipitated within reach of the jaws of 

 its concealed enemy. It feeds only on the blood or juice of 

 insects; and as soon as it has extracted these, it tosses the 

 dry carcass out of its den. Its next care is to mount the 

 sides of the pitfall and repair any damage it may have suf- 

 fered; and when this is accomplished, it again buries itself 

 among the sand at the bottom, leaving nothing but its jaws 

 above the surface, ready to seize the next victim. 



When it is about to change into a pupa, it proceeds in 

 nearly the same manner as the caterpillar of the water- 

 betony moth, {Ciicullia scrophularise). It first builds a 

 case of sand, the particles of which arc secured by threads 

 of silk, and then tapestries the whole with a silken web. 

 Within this it undergoes its transformation into a pupa, and 

 in due time it emerges in form of a four-winged fly, closely 

 resembling the dragon-flies, {Libellulae,) vulgarly and 

 erroneously called horse-stingers. 



The instance of the Ant-Lion naturally leads us to con- 

 sider the design of the Author of Nature, in so nicely 

 adjusting, in all animals, the means of destruction and of 

 escape. As the larger quadrupeds of prey are provided 

 with a most ingenious machinery for preying on the 



