Some Effects of Unilateral Ovariotomy in Rabbits

Abstract

A number of rabbits were partly ovariotomotised, the quantity of ovarian material removed being from one-half to five-sixths of the total present. These operations were performed before puberty. On breeding, the size of litter was found to be little smaller than that of control rabbits living under the same conditions. The number of eggs shed by the operated rabbits is but little different from that shed by the controls, suggesting that the basis of fecundity is to be found in somatic conditions rather than in the quantity of oöcytic material present. The incidence of foetal atrophy is greater in operated rabbits than in controls. Reasons are advanced in support of the view that the cause of this increased atrophy is different from that prevailing in normal rabbits. Normally, uterine accommodation is not a limiting factor in fertility, or in the size of young born. Hypertrophy of the remaining ovarian tissue occurs to a varying degree, and is proportionately the greater as more ovarian material is removed. This is probably due to the tendency to produce a definite number of ripe follicles at any one time. No hypertrophy of interstitial material could be detected. Ova are unable to travel from one uterine horn to the other across the vagina, though migration across the body cavity does occur. Unilateral ovariotomy does not affect the sex ratio of offspring in rabbits.