Notes on the Ant- Lion. 



603 



about on each side and backwards, (but never forwards, as 

 misrepresented in some figures), until the hole is made so 

 much deeper, and such a disturbance caused in the sides of 

 the hole, that the insect is almost sure to be brought down to 

 the bottom, when it is seized by the ant-lion, which immedi- 

 ately endeavours to draw it beneath the sand ; if it be very 

 boisterous, the ant-lion beats it about, holding it firmly with 

 its jaws, until it is too weak for further resistance. Hence, 

 as the head of the ant-lion is immersed in the sand, it is evi- 

 dent that the accounts given in popular works of the instinct 

 by which it throws the sand exactly in the direction of the 

 escaping prey, is not quite correct ; the act of throwing up 

 the sand when an insect has fallen into the pit and attempts 

 to escape, having evidently for its chief object, that of making 

 the pit deeper and more conical, and therefore more difficult 

 of ascent. 



On placing it on a flat surface of sand it first thrusts the 

 extremity of its body to a short distance in the sand, and then 

 by the assistance of its hind pair of legs drags itself back- 

 wards, its four fore legs being extended and trailing after it 



immoveably. Fig. 31, 

 A, represents a glass 

 containing sand ; a are 

 the traces on the sur- 

 face of the sand left by 

 the forelegs and jaws ; 

 b is the downward track 

 of the larva, gradually 

 deepening; c the jaws 

 of the larva exposed; 

 and d a little hillock of 

 sand raised by the body 

 of the ant-lion under- 

 neath. At this period 

 of the formation of its 

 burrow, the insect is en- 

 gaged in throwing back the sand. There is a very great ana- 

 logy between the motions of the head of this insect, and the 

 shutting of its jaws, and those of the larva of Cicindela. In 

 the ant-lion the head is lower, the neck being suddenly de- 

 flexed, and the base of the head beneath is very convex, and 

 is lower than the neck, just as in the larva of Cicindela. 



By watching the motions of the larva whilst on the surface 



of the sand, and before it has immersed itself, I perceived that 



it is by the retrograde motion of the hind pair of legs, which 



are directed backwards, that the insect effects its motions. — 



Vol. II.— No. 23. n. s. 3 n 



