We arrive now at the second principle. Is it true, as Wasmann contends, that the queen lays at will eggs of one or the other sex, that she voluntarily fertilizes certain eggs, and that she places the eggs, fertilized or not, in the appropriate cells!
At first glance the examination of the facts seems to justify the theory, for it is true that egg-laying workers, non-fertilized queens, and queens which have used their stock of spermatozoa, place their drone eggs by chance in the cells; it is equally established that normal queens lay eggs of either sex in the proper cells.
But it is not always the same. Dadant and Drory have shown that very fertile queens may in certain cases place eggs of males or workers in all kinds of cells. Drory (1875) states, moreover, that the queen places her male eggs in little cells when all the large cells have been taken away. Finally, the same Drory, and also Root and Dadant, have noted that worker eggs are laid in the large cells when all the little ones have been destroyed. From these facts we must conclude that there comes a time when the queen is obliged to lag either worker eggs or male eggs, and that, contrary to the theory, fecundation is not a voluntary act with her.
What is the cause of these abnormal deposits, and even the usual deposits which are almost always made in a series, the queen laying methodically male eggs in all the large contiguous cells and behaving the same with the little ones for the worker eggs? Since it is in the spring-time, before swarming, that the principal depositing of male eggs occurs, we may believe with Dadant that there comes a time when the seminal receptacle, fatigued by multiple contractions, enters into a condition of inertia which keeps it from emitting spermatozoa. But this muscular inertia appears to us to be independent of the high temperature of the hive, and, as we shall see, it is better to attribute it to a rhythm acquired by the bees in the course of the many generations which form the woof of their history.
However it may be, we must admit that the queens normally have the power of laying their male eggs in large cells and the worker eggs in the small ones. This is a very strange power,- involuntary, since it is subject to the desire to lay, and closely bound to the reflex mechanism of the seminal vesicle. This reflex has been attributed to the dimension of the cells, which, according to their size, do or do not compress the abdominal walls (Wagner) in forcing the queen to spread her legs or bring them together; but the history of the social wasps and, still more, that of the solitary bees lead us to think that the reflex originates in a psychic stimulation provoked by the sight of the dimensions and the form of the cells.
And to finish this critical study of Dzierzon's theory, we may say with Perez:
It is sufficient to recognize in the bee, not knowledge as to the sex of the egg it is about to lay, which one cannot reasonably admit, but the instinct to deposit in each kind of cell eggs of the appropriate sex. Selective faculty goes just that far and no farther.