It is about to descend into the oviduct, in its proper order, at its proper time; and the mother has no power to make another take its place.

It is this egg, necessarily this egg and no other, that will presently be laid upon the provisions, whether these be a mess of honey or a live prey; it alone is ripe, it alone lies at the entrance to the oviduct; none of the others, since they are farther back in the row and not at the right stage of development, can be substituted at this crisis.

Its birth is inevitable.
What will it yield, a male or a female?
No lodging has been prepared, no food collected for it; and yet both food and lodging have to be in keeping with the sex that will proceed from it.

And here is a much more puzzling condition: the sex of that egg, whose advent is predestined, has to correspond with the space which the mother happens to have found for a cell.

There is therefore no room for hesitation, strange though the statement may appear: the egg, as it descends from its ovarian tube, has no determined sex.