Page:The Effect of External Influences upon Development.djvu/33

Rh thoroughly explained. I refer to the neuters or workers of state-forming insects—bees, ants and termites. As is well known, these workers do not originate from special eggs, but it has been demonstrated in bees and termites, and shown to be very probable in the case of ants, that there is only one kind of egg, from which queens and workers as well as males arise. When female larvae are supplied with a very rich and nourishing diet, they give rise to queens; but workers are developed if the larvae receive scantier and less nourishing food. The differences between these two castes are manifold; but at present I wish to call your attention to one characteristic only, namely, the sterility of the workers—their relative or, in certain cases, absolute barrenness.

Let us inquire, in the first place, how this sterility has arisen. Many would possibly suppose that it is a direct consequence of the poorer nutrition of the larva. This view has frequently been maintained, and has been repeated by Herbert Spencer quite recently; but I cannot look upon it as a correct one in the sense implied. It is certainly true that bees have it in their power to cause a larva to become a queen or a worker according to the manner in which they feed it: it is equally true of all animals that they reproduce only feebly or not at all when badly and insufficiently nourished: and yet the poor feeding is not the causa efficiens of sterility among bees,