鷄ニ於ケル生殖生理ノ研究

Abstract

The object of the present study is to see the effect of castration on the growth of body and the weight of various organs in the domestic bowl. The results obtained may be summarized as follows.1. On compairing the body weight of thecastrated with that of the normal cocks it is found that the growth of the castrated begins to decrease from 3 weeks after castration. The difference of the body weight between them is remarkable at 6 weeks after castration; since then the castrated cocks grow vigorously and their weight becomes equal to that of the controls.2. As the result of castration the pituitary body is strikingly enlarged, the increase of weight being about 30 per cent in favour of the castrated.3. The thyroid glands of the castrated are considerably heavier than those of the normal cocks, the difference being on the average about 20 per cent.4. As in the mammal the thymus glands of capons are remarkably heavier than those of the normal cocks. When one compares the average weight of the thymus of the capons with that of the normal cocks, it is found that the thymus of the castrated appears to be about 200 per cent. heavier than that of the normal coeks.5. The hearts of the capons are strikingly smaller than those of the normal cocks, the average weight of the organs of capons being about 30 per cent. smaller.6, The male copulatory organ of the domestic fowl was first found by us in the ventral wall of the cloaca. It is found that this organ does not develop after castration; thus only a trace of it is to be found in the cloaca of capons.7. The remarkable effect of castration is also found on the Bursa fabricii which is to be completely disappeared at the sexual maturity. In capons this organ Kiyoshi Masui, Juro Hashimoto and Isamu Ono 37 is found to be the same size as in the young cocks.8. No effect of castration is produced in the weight of the suprarenal, spleen. kidney, pancreas and the length of the long bones.