MUTUAL AID AND COMMUNAL LIFE AMONG ANIMALS 391 



dinarily nice structural modifications which adapt the bee so 

 perfectly for its complex and varied businesses; and of the 

 tireless persistence of the workers until they fall exhausted 

 and dying in the performance of their duties. The community, 

 it is important to note, is a persistent or continuous one. The 

 workers do not live long, the spring broods usually not over 

 two or three months, and the fall broods not more than six or 

 eight months; but new ones are hatching while the old ones are 

 dying, and the community as a whole always persists. The 



a 



^_^ ^~* 



FIG. 244. Female (a), male (6) and worker (c) of an ant, Camponotus sp. 



queen may live several years, perhaps as many as five. 1 She 

 lays about one million eggs a year. 



There are many species of ants, two thousand or more, and 

 all of them live in communities and show a truly communal 

 life. There is much variety of habit in the lives of different 

 kinds of ants, and the degree in which the communal or social 

 life is specialized or elaborated varies much. But certain 

 general conditions prevail in the life of all the different kinds of 

 individuals sexually developed males and females that possess 

 wings, and sexually undeveloped workers that are wingless 

 (Fig. 244). In some kinds the workers show structural differ- 

 ences among themselves, being divided into small workers, 

 large workers, and soldiers. The workers are, as with the 



1 A queen bee has been kept alive for fifteen years. 



