WASPS, SOCIAL AND SOLITARY 



used by Ammophila, with its chain of ganglia, in the 

 Araneidae the whole central nervous system, including 

 the brain and the ventral cord, forms a single mass, 

 pierced by the oesophagus. The greater part of this mass, 

 which lies behind the oesophagus, represents the fused 

 ventral cord from which the nerves radiate. It is evident 

 that a thrust given in almost any part of the ventral face 

 of the cephalothorax, or even on either side of the an- 

 terior half of its edges, would reach the nervous centre. 

 With these facts before us let us turn to the notes made 

 upon the condition of the spiders that had been stung 

 and stored up in the nests of the straw-stack. By the 

 "first cell" we mean the last one stored, which was 

 naturally the first one opened. 



July 1 1. Opened a nest of rubrocinctum. The first cell 

 contained fourteen live spiders with a newly laid egg. 

 Some of the spiders were very lively, moving spontaneously. 

 Second cell, ten spiders, one dead, others alive, and an 

 egg. Third cell, eight spiders, three dead and five alive, 

 and the egg. 



July 12. In each of the first and second cells one spider 

 has died since yesterday, while in the third there is no 

 change in their condition. The egg in the third cell hatched 

 at nine in the morning, and the one in the second cell at 

 three in the afternoon. 



July 13. In the first cell all the spiders are dead but one, 

 186 



