238 ANIMAL INTELLIGENCE. 



the triangular end of the case, it entirely changed the 

 original plan, and made that end the head which had been 

 first designed for the tail.' 



Another remarkable case of the variation of instinct in 

 the Lepidoptera is stated by Bonnet. There are usually, 

 he says, two generations of the Angoumois moth : the first 

 appear in early summer, and lay their eggs upon the ears 

 of wheat in the fields ; the second appear later in the 

 summer, or in the autumn, and these lay their eggs upon 

 wheat in the granaries ; from these eggs there comes the 

 first generation of next year's moths. This is a highly 

 remarkable case — supposing the facts to be as Bonnet 

 states ; for it seems that the early summer moths, although 

 born in the granaries, immediately fly to the unreaped 

 fields to lay their eggs in the standing corn, while the 

 autumn moths never attempt to leave the granaries, but 

 lay their eggs upon the stored wheat.^ 



Westwood says that — 



A species of Tasmanian caterpillar [Noctua Ewingii) swarms 

 over the land in enormous companies, which regularly begin to 

 march at four o^clock in the morning, and as regularly halt at 

 midday. Liparis chrysorrhaca, a kind of caterpillar, spins for 

 the winter a common web, in which several hundred individuals 

 find a common shelter.*^ 



According to Kirby and Spence, — 



The larva of the ichneumon, while feeding upon its caterpillar 

 host, spares the walls of the intestines until it is time for it to 

 escape, when, the life of the caterpillar being no longer necessary 

 to its development, it perforates these walls.^ 



The larvae Theda isocrates live in a group of seven or eight 

 in the fruit of pomegranate. In consequence of their excava- 

 tions within the fruit, the latter is apt to fall ; and to prevent 

 its doing so the larvae throw out a thread of attachment where- 

 with to secure the friiit to the branch, so that if the stalk withers, 

 this thread serves to suspend the fruit.'^ 



The caterpillar of the Bombyx moth, which is a native of 

 France, exhibits very wonderful instincts. The larva is gre- 

 garious in its habits, each society (family) consisting of perhaps 



» (Euvres, ix., p. 370. ^ Trans. Ent. Soc, vol. ii. 



3 Introd. Ent., Letter xi. 



* Westwood, Trans. Ent. Soc, vol. ii., p. 1. 



