Premature Expulsion of Eggs by Hens Following Injection of Whole Posterior Pituitary Preparations

IN 1921 Riddle reported that the administration of whole posterior pituitary substance (pituitrin of Parke, Davis and Company) to ring doves, pigeons, and common fowl caused the premature expulsion of eggs from their oviducts. Riddle included in his published results data on only two hens; these laid approximately four hours prematurely, one 33 and the other 45 minutes following either intramuscular or hypodermic injection of pituitrin. In the experiments described here the action of whole posterior pituitary preparations on the premature expulsion of eggs from the oviducts of domestic fowl has been further investigated. A part of the data has been reported upon in abstract form (Burrows and Byerly, 1940). MATERIALS AND PROCEDURES Most of the hens used were Rhode Island Reds in their second year of production. Excepting a few birds used in preliminary injections, they were kept in batteries. The hens were taken from their their cages, injected . . .