POLYMORPHISM. 91 



since they have not only produced a wingless form of the worker, in 

 addition to the winged female, or queen, but in many cases also two 

 distinct castes of workers known as the worker proper and the soldier. 



Different authors have framed very different conceptions of the 

 phylogenetic beginnings of social life among the Hymenoptera and 

 consequently also of the phylogenetic origin and development of poly- 

 morphism. Thus Herbert Spencer (1893) evidently conceived the 

 colony as having arisen from consociation of adult individuals, and 

 although he unfortunately selected a parasitic ant, the amazon (Poly- 

 ci't/iis ntfcscens'), on which to hang his hypothesis, there are a few 

 facts which at first sight seem to make his view applicable to other 

 social Hymenoptera. Fabre (1894) once found some hundreds of 

 specimens of a solitary wasp (.-Immophila hirsnta) huddled together 

 under a stone on the summit of Alt. Ventoux in the Provence, at an 

 altitude of about 5,500 feet, and Forel (18/4) found more than fifty 

 dealated females of Formica rufa under similar conditions on the 

 Simplon. I have myself seen collections of a large red and yellow 

 Amblyteles under stones on Pike's Peak at an altitude of more than 

 13,000 feet, and a mass of about seventy dealated females of Formica 

 c/nara apparently hibernating after the nuptial flight under a stone 

 near Austin, Texas. I am convinced, however, that such congrega- 

 tions are either entirely fortuitous, especially where the insects of one 

 species are very abundant and there are few available stones, or, that 

 they are, as in the case of F. nifa and ynara, merely a manifestation 

 of highly developed social proclivities and not of such proclivities in 

 process of development. 



A very different view from that of Spencer is adopted by most au- 

 thors, who regard the insect colony as having arisen, not from a chance 

 concourse of adult individuals, but from a natural affiliation of mother 

 and offspring. This view, which has been elaborated by Marshall 

 ( 1889) among others, presents, many advantages over that of Spencer, 

 not the least of which is its agreement with what actually occurs in 

 the founding of the existing colonies of wasps, bumble-bees and ants. 

 These colonies pass through an ontogenetic stage which has all the 

 appearance of repeating the conditions under which colonial life first 

 made its appearance in the phylogenetic history of the species the 

 solitary mother insect rearing and affiliating her offspring under condi- 

 tions which would seem to arise naturally from the breeding habits of 

 the nonsocial Hymenoptera. The exceptional methods of colony for- 

 mation seen in the swarming of the honey bee and in the temporary 

 and permanent parasitism of certain ants, are too obviously secondary 

 and of too recent a development to require extended comment. The 



