Ovulation and degeneration of ova in the rabbit

It has long been held that ovulation invariably occurs in all animals at each period of œstrus. I have already shown (Nos. 13, 14, 15) that this is not necessarily true for menstruating animals. In other polyœstrous animals also there seems reason to believe that when coition is prevented during the first few recurrent œstrous periods, ovulation is interfered with during the subsequent periods, for conception is then much more uncertain than it is if coition occurs when the sexual season first appears.