MALES AND FEMALES 



THESE differ from each other very greatly in 

 many cases. Eccentricity in structure almost 

 always occurs in the male ; excess of coloration 

 usually in the female. In size the male is 

 generally the smaller and the less robustly 

 built of the two. Among the pollen-collectors, 

 the male is usually less densely clothed with 

 hairs than the 9 . In the fossors this rule is 

 rather reversed, but in that section neither sex 

 is densely clothed with hairs as are most of 

 the pollenigerous bees. 



The male has normally thirteen joints in its 

 antennae, and the female only twelve. There 

 are exceptions to this rule amongst the ants 

 and in certain fossors of the genus Crabro, some 

 species of which have the antennae considerably 

 distorted, and have two joints welded apparently 

 into one. Another distinction between the 

 sexes is that the male has seven dorsal segments 



