THE EVOLUTION OF INSTINCT 129 



to degenerate into an almost shapeless mass devoted entirely 

 to feeding and the production of eggs. If now the develop- 

 ment of some of the females could be checked, by insuffi- 

 cient nutrition at an earlier period of metamorphosis we 

 should have a caste of sterile forms more highly organized in 

 structure and of more varied instincts than the fertile females. 

 It would certainly be an error to conclude that the superiority 

 of the sterile individuals was due to their having independ- 

 ently acquired, since the differentiation of the caste, charac- 

 ters which were not a part of the legacy of their parents. 

 This is, I think, a fair statement of the neo-Lamarckian 

 side of the question. Granting that the theory is otherwise 

 acceptable the Lamarckian doctrine is still open to serious ob- 

 jections when applied to the instincts of neuter insects. 

 It would compel us to assume that all the adaptive struc- 

 tures and instincts of the worker bee were but the survival of 

 a more primitive period of social evolution before the complete 

 separation of the fertile and sterile castes, when presumably 

 they might have been evolved through the inherited effects 

 of habit. And not only should we have to assume that there 

 had been no improvement in the non-reproductive activities 

 since the queen had ceased performing them, but the theory 

 would lead us to expect a certain amount of deterioration 

 through disuse. It certainly cannot be supposed that 

 during a period long enough for the queen to lose her wax 

 glands, pollen basket, and all her instincts for gathering 

 honey, making comb, and caring for the young, the structures 

 and instincts of the workers should have suffered no degenera- 

 tion. Instead of this there has undoubtedly been a decided 

 improvement. Nowhere in social bees do we find so high a 

 degree of structural adaptation, such varied activity, such 

 perfect workmanship in the construction of comb with its 

 varied cells for queen, drone and worker, and such complex 



