2 7 o THE WONDERS OF INSTINCT 



such as, for instance, Helix variabilis, Drap., who, in 

 the hot weather, collects in clusters on the stiff stubble 

 and other long, dry stalks by the road-side and there 

 remains motionless, in profound meditation, throughout 

 the scorching summer days. It is in some such resting- 

 place as this that I have often been privileged to light 

 upon the Lampyris banqueting on the prey which he had 

 just paralyzed on its shaky support by his surgical 

 artifices. 



But he is familiar with other preserves. He frequents 

 the edges of the irrigating ditches, with their cool soil, 

 their varied vegetation, a favorite haunt of the Mollusc. 

 Here, he treats the game on the ground ; and, under these 

 conditions, it is easy for me to rear him at home and to 

 follow the operator's performance down to the smallest 

 detail. 



I will try to make the reader a witness of the strange 

 sight. I place a little grass in a wide glass jar. In this 

 I install a few Glow-worms and a provision of snails of 

 a suitable size, neither too large nor too small, chiefly 

 Helix variabilis. We must be patient and wait. Above 

 all, we must keep an assiduous watch, for the desired 

 events come unexpectedly and do not last long. 



Here we are at last. The Glow-worm for a moment 

 investigates the prey, which, according to its habit, is 

 wholly withdrawn in the shell, except the edge of the 

 mantle, which projects slightly. Then the hunter's 

 weapon is drawn, a very simple weapon, but one that 

 cannot be plainly perceived without the aid of a lens. It 

 consists of two mandibles bent back powerfully into a 



