Rationing According to Sex 



noted as favourable during the working-sea- 

 son, a few handfuls of cocoons of various 

 Digger-wasps, notably of the Bee-eating Phil- 

 anthus, who has just furnished us with an in- 

 ventory of provisions. Surrounding these 

 cocoons and thrust against the wall of the 

 cell were the remnants of the victuals — 

 wings, corselets, heads, wing-cases — a count 

 of which enabled me to determine how many 

 head of game had been provided for the 

 larva, now enclosed in its silken abode. I 

 thus obtained the correct list of provisions 

 for each of the huntress' cocoons. On the 

 other hand, I estimated the quantities of 

 honey, or rather I gauged the receptacles, 

 the cells, whose capacity is proportionate to 

 the mass of the provisions stored. After 

 making these preparations, registering the 

 cells, cocoons and rations and putting all my 

 figures in order, I had only to wait for the 

 hatching-season to determine the sex. 



Well, I found that logic and experiment 

 were in perfect agreement. The Philanthus- 

 cocoons with two Bees gave me males, always 

 males; those with a larger ration gave me 

 females. From the Tachytes-cocoons with 

 double or treble" that ration I obtained fe- 

 males. When fed upon four or five Nut- 

 weevils, the Sand Cerceris was a male ; when 

 225 



