Bramble-bees and Others 



the Idea of an Invariable succession first of 

 females and then of males, the Idea which 

 occurs to us on examining the new nests. If 

 this rule were a constant one, we should be 

 bound to find In the old domes at one time 

 only females, at another only males, accord- 

 ing as the laying was at its first or at its 

 second stage. The simultaneous presence of 

 the two sexes would then correspond with the 

 transition-period between one stage and the 

 next and should be very unusual. On the con- 

 trary. It Is very common; and, however few 

 cells there may be, we always find both fe- 

 males and males in the old nests, on the sole 

 condition that the compartments have the 

 regulation holding-capacity, a large capacity 

 for the females, a lesser for the males, as we 

 have seen. 



The old male cells can be recognized by 

 their position on the outer edges and by their 

 capacity, measuring on an average the same as 

 a column of sand 31 millimetres high in a 

 glass tube 5 millimetres wlde.^ These cells 

 contain males of the second or third genera- 

 tion and none but males. In the old female 

 cells, those In the middle, whose capacity is 



ii.2i X .195 inches. — Translator's Note. 



xsS 



