Adenohypophysis and growth in tadpoles of Rana temporaria

Abstract

Growth of the Rana temporaria tadpole was investigated after (1) adenohypophysectomy, (2) autografting the adenohypophysis to the tail, and (3) homografting an extra adenohypophysis into the tail of the otherwise normal tadpole. All operations were performed using the early tail-bud embryo. The three tadpole types displayed (1) reduced, (2) about normal, and (3) somewhat increased growth rates, as compared to the controls. The interpretation of the results is that the adenohypophysis is necessary for normal growth rate and stimulates growth, probably by producing growth-promoting hormone(s), which seem to be secreted at the same rate as when the gland is removed from direct hypothalamic control.