The Time and Place of Fertilization of the Golden Hamster Egg

The middle and caudal third of the ampulla tubae are the regions where most of the eggs of Mesocricetus auratus Waterhouse are fertilized. The earliest fertilization resulting from evening matings prior to ovulation (assuming the ovulation peak to be at 3 a.m.) were obtained at 2 hours after ovulation. When copulation occurred the morning after ovulation, fertilized ova were not obtained at 2 hours after mating, but they were at 4 hours. The time of fertilization is most frequently between the 2nd and 10th hour after ovulation. About 91 per cent, of the eggs are fertilized during this period. On the basis of existing data it is not possible to speak of a family-specific or even an order-specific fertilization site for the mammalian egg.