1OO 



ANTS. 





rise- to a male or a female. And as the queen represents the typical 

 female form of the species, the problem of polymorphism is to account 

 for the various worker forms, and those like the soldiers, pseudogynes 

 and ergatoid females which are intermediate between the worker and 

 the queen. The ergatomorphic males are usually regarded as inheriting 



worker characters. Thus the problem of 

 polymorphism centers in the. development 

 of the worker. It must suffice in this 



t place to give the briefest possible state- 



ment of the views of the various authors 

 who have endeavored to account for the 

 development of this caste. These authors 

 IB may be divided into three groups : 

 i. Those who believe with Weismann 

 that the various castes are represented in 

 the egg by corresponding units (determi- 

 nants). Fertilization is then regarded as 

 the stimulus which calls the female deter- 

 minants into activity and meagre feeding 

 the stimulus which arouses the worker- 

 producing determinants .in young larvre 

 arising from fertilized eggs. Such an 

 explanation is obviously little more than 

 a restatement or " photograph " of the 

 major problem. It seeks to account for the 

 and minor of Camponotns ameri- adaptive characters of the worker forms 



catnts. (Photograph by T. G. i i , ,. r 



Hubbard and Dr. O. S. Strong.) b y natural selection acting on fortuitous 



congenital variations. 



2. Those who believe with Herbert Spencer that there is no such 

 predetermination of the various female castes, but that these are pro- 

 duced epigenetically by differences in the feeding of the larvae. The 

 workers simply arise from larvse that are inadequately fed but are 

 nevertheless able to pupate and hatch when only a part of their growth 

 lias been completed. This is not, like the preceding view, a restatement 

 of the problem, since the modifications produced by inadequate feeding 

 are conceived as somatic and not as germinal, but it fails to explain 

 how the worker caste acquires its adaptive characters, unless this caste 

 is supposed to reproduce with sufficient frequency to transmit acquired 

 somatic modifications to the germ-plasm of the species. 



3. A third group of investigators believes with Emery that the 

 germ-plasm of the social Hymenopteron is indeed implicated in the 

 problem, not as possessing separate sets of determinants, but as being 



FIG. 6 1. Workers 



