9 



ANTS. 



M>cial Ilymcnoptera, seems to be evident from the fact that the male- 

 usually if not always develop from unfertilized, the females from 

 fertilized eggs. 



While the 1 nun'ble-bees and wasps show us the ancient stages in 

 the development of polymorphism, the ants as a group, with the ex- 

 ception of a few parasitic genera that have secondarily lost this 

 character, are all completely polymorphic. It is conceivable that the 



FIG. 53. Cryf>toccrus rarians. (Original.) a. Soldier: b. same in profile: c. head 

 of same from above ; d. worker ; e. female : /, male. 



development of different castes in the female may have arisen inde- 

 pendently in each of the three groups of the social Hymenoptera, al- 

 though it is equally probable that they may have inherited a tendency 

 to polymorphism from a common extinct ancestry. On either hypoth- 

 esis, however, we must admit that the ants have carried the develop- 

 ment of the female castes much further than the social bees and wasps. 



