Implantation of Pineal Glands in the Leghorn Fowl.

Abstract

Foà reported a precocious development of the secondary sex structures in pinealectomized males of the domestic fowl. The growth of the body of the cockerels was retarded during the first 2 or 3 months following the operation, but after this period of retarded growth they attained the weight of normal adults. No noticeable effect was produced on the operated hens. Izawa observed a precocious increase in body weight as well as in the size of the comb in both sexes. Christea obtained contradictory results. He observed a marked retardation in the development of the secondary sex characters in male birds in which the pineal gland had been removed. The development of the body was not particularly delayed. Badertscher did not observe any significant difference in the development of the secondary sex characters nor in body weight between pinealectomized birds and the controls. In an effort to collect additional data on the function of epiphysis, implantation of the pineal gland was resorted to as a possible point of attack, a method that has proved successful in the study of some of the other endocrine glands. Because of the prevalent idea among a number of investigators that the pineal gland is concerned with the rate of maturity, pineal bodies from adults were implanted subcutaneously into infant chicks; and pineal glands from infant chicks and from embryos in the latter stages of incubation were implanted into half grown birds, birds in which the secondary sex characters showed marked sex dimorphism. In the first series of experiments 2 infant male chicks were used. The one received 14 implants from adult birds over a period of 28 days; the other, 25 over a period of 44 days. In the latter series of experiments, 2 females and 2 males were employed.