252 THEORETICAL BIOLOGY 



this way, but by an inter-adjustment that expresses a plan. 

 ^ Colonies of this kind we call communities. 



In addition, animal communities are characterised by a 

 marked differentiation of the various persons, a differentiation 

 which also sometimes occurs in colonies. The persons, 

 especially in the familiar bee and ant communities, fall into 

 groups according to their special vocation ; and these groups 

 differ widely from one another in their bodily conformation. 

 Each group serves some one function-circle more particularly : 

 there are soldiers for driving off enemies, workers for collect- 

 ing the food, and queens serving for reproduction. It is 

 impossible not to see in the community as a whole a modified 

 organism, which has its own function-circles in addition to 

 those of the several persons. 



Nevertheless, the individual persons arise from independent 

 eggs, which are laid by the queen. Already in the ovary the 

 genes are distributed in these eggs in different groups accord- 

 ing to the vocation, or, as in the bees, a suppression or an 

 accentuation of certain gene-groups is effected by means 

 of different methods of breeding. 



The result is always an independently functioning unit, the 

 parts of which are represented by the several independent 

 persons. Whereas the organs of the free-living single animal 

 are equally developed in every direction of the function-circles, 

 the individual animals of the community, as the result of the 

 common life which robs them of certain parts of these, are 

 in a position to develop themselves with special reference to 

 one function. The queen-bee can devote herself exclusively 

 to the work of reproduction, for she is provided with food 

 and protected from enemies by the workers. Conversely, 

 the workers, relieved of the business of producing young, 

 can develop with reference to fighting and food-capture. 



This separation of the function-circles goes furthest in 

 the case of the traveller ants. The long procession of these 



