226 COMPARATIVE PHYSIOLOGY OF THE BRAIN 



trace and was guided reflexly when it carried the cat- 

 erpillar to the nest. The repeated attempts to climb 

 the wall of the yard which first attracted my atten- 

 tion indicate that the wasp remembered the location 

 of the nest. The fact that it returned to fetch the 

 caterpillar indicates that it remembered having 

 dropped it, and also where it had been dropped. The 

 zigzag character of its flight shows that it was not 

 guided reflexly. 



While these animals without doubt possess asso- 

 ciative memory they possess little " intelligence." 



I mentioned that the Ammophila covered the hole 

 in which it had buried the caterpillar. In order to 

 cover it, the wasp had to pick up little grains of 

 sand in the neighbourhood of the hole and carry them 

 in its mandibles to the hole. Once, while it had its 

 back turned to the nest and was picking up a grain of 

 sand, I covered the hole with a clover blossom. The 

 wasp was no longer able to find the hole. It ran and 

 flew about in the most excited manner, returning each 

 time to the place where the hole had been, without 

 being able to discover it. I finally removed the 

 flower, and the wasp immediately found the hole and 

 continued covering it with sand. The blossom with 



O 



which I covered the hole weighed considerably less 

 than the caterpillar which the wasp carried with such 

 ease between its mandibles. The fact that the wasp 

 keot returning to the spot where the hole was, indi- 

 cates again the existence of memory in these animals. 

 Bethe's conclusions have been criticised by Was- 



