OBSERVATIONS INDICATING A SEX CYCLE IN THE MALE RABBIT

Abstract

ABSTRACT Recently some physiological characteristics of a sex cycle in male animals have been demonstrated. However, nothing is known at present about any morphological expressions of this cycle, and particularly about any rhythmical variation in exfoliation of cells comparable with that of the vaginal mucous membrane. On the assumption that such a rhythm may occur in the male urethra, the exfoliation of cells in this organ has been studied by taking daily smears. Cyclically varying frequencies of four different types of exfoliated cells, mainly in an immature stage, were demonstrated. Only a fifth type of cells, characterized by cornification and nuclear degeneration, is not subjected to such rhythmical variation. The mean duration of these cycles is about four days. Simultaneous investigations on the seminal volume and body temperature showed some relation to the cycle of cell desquamation. The results give additional evidence for the existence of a male sex cycle, probably with a hormonal background.