Page:The Effect of External Influences upon Development.djvu/51

Rh and imago, the origin of the art of rearing workers or queens at will, and for all the bodily improvements and degenerations which have taken place.

The effects produced by natural selection in the formation of insect-states are certainly wonderful and manifold; and we are quite justified in asking whether such intensive processes of selection are specially possible in the case of the state-forming insects. Several years ago Wolff gave expression to the view that selection was out of the question in this case, for 'the individuals struggling for existence and those offering varieties for selection' are not the same,—the first being represented by the hive, the second by the single persons which compose it. It is true that variations of single individuals of the many thousands in a hive would be quite ineffective in the struggle for existence in which the hive as a whole has to take part. But Wolff has overlooked the fact that the hive as a whole, if not an absolute unit, varies like one, inasmuch as all its members are the offspring of one or at most of a few mothers. The fact that there is ony one queen in the hive considerably simplifies and facilitates the processes of selection, all the partners of the society being sons and daughters of the same father and mother. According to Grassi's researches this is also true as regards some of the termites at the present day: in the case of Calotermes flavicollis there is only one true queen; and though