Returning to the subject of the limitation of the reproduction of the community to a single pair, we may remark that _a priori_ one would suppose such a limitation to be excessively unfavourable to the continuation of the species; and as it nevertheless is the fact that this feature is almost, if not quite, without exception {379}in Insect societies, we may conclude that it is for some reason absolutely essential to Insect social life. It is true that there are in Termitidae certain partial exceptions, and these are so interesting that we may briefly note them. When a royal cell is opened it usually contains but a single female and male, and when a community in which royal cells are not used is inspected it is usually found that here also there are present only a single fertile female and a single king. Occasionally, however, it happens that numerous females are present, and it has been noticed that in such cases they are not fully matured females, but are imperfect, the condition of the wings and the form of the anterior parts of the body being that of adolescent, not adult Insects. It will be recollected that the activity of a community of Termites centres round the great fertility of the female; without her the whole community is, as Grassi graphically puts it, orphaned; and the observations of the Italian naturalist make it clear that these imperfect royalties are substitution queens, derived from specimens that have not undergone the natural development, but have been brought into use to meet the calamity of orphanage of the community. The Termites apparently have the power of either checking or stimulating the reproductive organs apart from other organs of the body, and they appear to keep a certain number of individuals in such a condition that in case of anything going wrong with the queen, the reserves may be brought as soon as possible into a state of reproductive activity. The individuals that are in such a condition that they can become pseudo-royalties are called complementary or reserve royalties, and when actually brought into use they become substitution royalties. It is not at present quite clear why the substitution royalties should be in such excess of numbers as we have stated they were in the case we have figured (Fig. 236), but it may be due to the fact that when the power of the community is at a certain capacity for supporting young a single substitution royalty would not supply the requisite producing power, and consequently the community adopts a greater number of the substitution forms. Termites are utterly regardless of the individual lives of the members of the community, and when the reproductive powers of the company of substitution royalties become too great, then their number is reduced by the effective method of killing and eating them.