ABSTRACT
When we turn from the facts of polymorphism as ascertained by observation and experiment to their interpretation we at once find ourselves involved in the physiological problems of ontogeny and growth, of phylogeny, or evolution and of behaviour, or the activities of the organism—in fact in all the really fundamental biological problems. For there is no a priori reason to suppose that the development of the castes among social insects requires any new or unusual explanation since intelligent behaviour, which plays a rôle so considerable and so unique in the interpretation of human societies and gives such scope for diversity of opinion among sociologists and philosophers, is so feeble even in the social Aculeata as to be quite negligible in comparison with their physiological and instinctive activities. In my paper on polymorphism, published in 1907, I endeavoured to treat the subject from a number of points of view, but here it seems best to reduce the problem to the alternative between predetermination and epigenesis. This problem, as is well known, has long divided biologists into two camps comparable to those among philosophers, who are either Platonists or Aristotelians, idealists or realists, nativists or empiricists, instinctivists or environmentalists, etc. The morphologist, primarily an observer, naturally inclines more to the predeterministic, the physiologist, primarily an experimentalist, to the epigenetic view. Each tends to a one-sided interpretation of the facts, and both, we are now convinced, are right—there is predeterminism and there is epigenesis in organic development, but there is still abundant opportunity for divergent opinions on the scope of the two factors in any particular case. In fact, present day geneticists and physiologists are nearly as widely separated as were the old preformationists, or evolutionists and the epigenesists.
