THEORY OF THE DEVELOPMENT OF ORGANISMS 125 



have the high-pitched voice and the peculiarities 

 of the larynx found in women. 



As much as sexual dimorphism, the phenomena 

 of polymorphism show the enormous influence 

 exerted by external forces upon correlated varia- 

 tion of the parts during development, and in this 

 way upon the final structure. 



In the question of polymorphism it is worth 

 while to discuss at some length the extreme poly- 

 morphism exhibited in the case of some of the 

 colonial animals first, because the matter has 

 recently occasioned an important controversy be- 

 tween Herbert Spencer and Weismann ; and, 

 secondly, because the discussion will serve to 

 make still more clear the difference between my 

 views and those of Weismann upon the nature of 

 the process of development. 



Among the colonial insects there arise, in 

 addition to males and females, sexless individuals 

 known as neuters. These in certain cases are very 

 different from both males and females in structure 

 and in social instincts. 



Among bees there are the queens, sexually 

 mature females ; the workers, females whose sexual 

 organs are rudimentary, and parts of whose bodies 

 the stings, the wings, the hind legs, with their 

 pollen-collecting apparatus are peculiarly formed; 

 and, lastly, the males, or drones. 



In many of the ant and termite colonies still 

 greater differences exist between the different sets 

 of individuals. In addition to males and females, 

 there are sexless workers, and these in many species 



