STUDIES ON THE PHYSIOLOGY OF REPRODUCTION IN BIRDS

Abstract

The literature dealing with blood fat as a sex differential, and on changes in blood fat and P during the reproductive cycle, is reviewed. From Protozoa to man there is meager but uncontradictory evidence that fat metabolism is not equal in c?1 and 9 . This is regarded as a primary sex difference. Considered as groups, normal cT ringdoves are shown to have less blood fat than normal 9 in the "resting" or any other stage of the reproductive cycle. During the ovulation cycle of ringdoves the amount of alcohol-ether-soluble substance in whole blood is increased 35% above normal. The P in this extract is increased approximately 50% above normal. This recurs with each ovulation period. Blood fat and P reach their maximum 45-67 hrs. earlier than other cyclic changes previously noted (suprarenal hypertrophy, blood sugar, and Ca increase) which were coincident with the ovulation period. Because of the known relations of the ovary to fat metabolism, this suggests that the ovary itself, rather than suprarenals or parathyroids, is directly responsible for the entire cycle of changes associated with ovulation.