The Determination of the Castes of Social Insects (Concluded)

Abstract

In this second and concluding paper of the review the author presents evidence that caste determination in termites is brought about by extrinsic, rather than by intrinsic factors for which no valid evidence exists. Each egg and each young nymph has the capacity up to a certain point of becoming an individual of any of the terminal types characteristic of the species. Food is not considered to be one of the determining factors. There is evidence for inhibiting influence of soldiers on soldier production, and of functioning reproductives upon production of neotenics. Different colonies exhibit tendencies toward neotony in varying degrees. There is a lack of correlation between viability and reproductivity, and in some groups a negative correlation between mortality and viability.