Histological Changes in the Ovary of the Hopping-Mouse Notomys Alexis During Lactation.

Abstract

The histological structure of the ovary of the lactating hopping-mouse is described. Two sets of corpora lutea are usually present, one of which appears to degenerate fairly rapidly during lactation and is thus considered to be the corpora lutea of pregnancy. Spontaneous ovulation usually occurs after parturition; thus corpora lutea of lactation are formed which appear to remain healthy-looking throughout most of lactation. Oocytes were flushed from Fallopian tubes immediately after parturition, but then not again until at least day 10 of lactation. Vesicular follicles were not present after post-partum ovulation, but had usually developed by day 5. In females suckling three or more young, however, maximum follicular size did appear to be somewhat inhibited, compared to that in females suckling one young, from days 5 to 11 of lactation; by day 15 larger vesicular follicles had developed and recently formed corpora lutea were present in one individual.