.184 IXSECT ARCHITECTURE. 



In the 'Magazine of Natural History,' 1838, p. 601, 

 Mr. Westwood gives a very interesting acconnt of the mode 

 in which the ant-lion proceeds in the excavation of its 

 pitfall, as witnessed by himself in specimens procured in 

 the Pare de Belle Yue, near Paris, where, at the foot of 

 a very high sand-bank, these pits were numerous, and of 

 various sizes, but none exceeded an inch and a half or 

 two inches in diameter, and two-thirds of an inch deep. 

 " The ant-lions were of various sizes, corresponding to 

 the size of their retreats. I brought many of them to 

 Paris, placing several together in a box filled with sand. 

 They, however, destroyed one another wdiilst shut up in 

 these boxes ; and I only succeeded in bringing three of 

 them alive to England, one of which almost immediately 

 afterwards (on the 23rd of July) enclosed itself in a globu- 

 lar cocoon of fine sand. The other two afforded me man}^ 

 opportunities of observing their proceedings. They were 

 unable to walk forwards, — an anomalous circnmstance, and 

 not often met with in animals furnished with well-deve- 

 loped legs. It is generally backwards, working in a spiral 

 direction, that the creature moves, pushing itself backwards 

 and downwards at the same time, the head being carried 

 horizontally, and the back much arched, so that the ex- 

 tremity of the body is forced into the sand. In this 

 manner it proceeds backwards (to use an Tlibernianism), 

 forming little mole-hills in the sand. But it does not 

 appear to me that this retrograde motion has anything to 

 do with the actual formation of the cell, since, as soon as it 

 has fixed upon a spot for its retreat, it commences throwing 

 up the sand with the back of its head, jerking the sand 

 either behind its back or on one or the other side. It shuts 

 its long jaws, forming them into a kind of shovel, the sharp 

 edges of which it thrusts laterally into the sand on each 

 side of its head, and thereby contrives to lodge a quantity 

 of the sand upon the head as well as the jaws. The motion 

 is in fact something like that of the head of a goat, 

 especially when butting sideways in play. In this manner 

 it contrives to throw away the sand, and by degrees to 

 make a hole entirely with its head, the ft^ur legs not 



