James Plummer Schooley

Effective Stimulation of Crop-Sacs by Prolactin in Hypophysecto-mized and in Adrenalectomized Pigeons

Summary In all of 20 pigeons completely hypophysectomized from 1 to 287 days earlier the crop-sacs were stimulated by prolactin to proliferation, and often to crop-milk formation within 4 days. These complete responses were obtained in both very immature and in adult individuals. Quantitative measurements made on the operated adults show, however. that their crop-sac response is only about one-eighth that of unoperated mature pigeons. Complete adrenalectomy did not prevent the usual response of the crop-sacs to prolactin in a test started 4 days after operation. Thyroidectomy did not significantly affect tlie usual crop-sac response to prolactin in a pigeon operated 176 days earlier.

Absence of Follicle-Stimulating Hormone in Pituitaries of Young Pigeons

Summary The testes of immature ring doves are measurably stimulated by implants of 1 immature (29-44 days) rat pituitary daily for 10 days; one adult common pigeon pituitary daily for 10 days gives much greater stimulation; stimulation can be obtained from fewer than 5 adult pigeon pituitaries 30 pituitaries of immature but nearly full grown pigeons (1.8 to 2.3 months from beginning development) implanted in groups of 3 daily for 10 days give no detectable stimulation. These results confirm an earlier indication from growth rate of testes in these birds : Pigeons less than 2.3 months old (1.8 months after hatching) and ring doves of less than 3.0 months (2.5 months after hatching) are to be considered as animals in which the production of F.S.H. has not yet been initiated. When anterior pituitary hormones, or extracts of this tissue, are injected into these birds it must be granted that their action is obtained on an intact organism free from follicle-stimulating hormone, and that the injected material serves neither to reduce nor to induce an output of F.S.H. from the birds own pituitary.