146 THE BIOLOGICAL BASIS OF INDIVIDUALITY 



hyperemia in transplants in completely thyroidectomized hosts, as compared 

 to animals in which a part of their own thyroid glands had been left intact. 

 Haberer and Salzer (1909), in rabbits, and more recently, Ingle and Cragy, 

 in rats, likewise noted a better vascularization and better growth of the acini 

 in completely thyroidectomized animals than in those in which a part of the 

 thyroid had remained. Halsted (1909), in the case of the parathyroid gland, 

 found in dogs a better growth of autogenous parathyroids in animals in which 

 their own glands had been completely extirpated ; he believed that an endocrine 

 deficiency is necessary not only for the better development, but also for the 

 survival of an autogenous graft. However, this opinion is based apparently 

 on a relatively small number of cases, in which the autogenous parathyroid 

 transplants were recovered in parathyroidectomized dogs, and this investiga- 

 tor is very cautious in stating his conclusion. 



There are, however, experiments with transplantation of other endocrine 

 organs, in which the effect of an endocrine deficiency on the survival of 

 transplants of such organs is greater. Thus the experiments on the grafting of 

 adrenal cortex by Wyman and Turn Suden, by Ingle, Nilson, Higgins and 

 Kendall, as well as those of Lux, Higgins and Mann, showed that successful 

 transplantation of the adrenal cortex depends, in the first place, upon the 

 genetic relationship between donor and host, better results being obtained in 

 inbred rats in litter mates than in less nearly related animals. Furthermore, 

 transplants from newborn rats are more favorable than those from older 

 donors, but in addition, a deficiency in adrenal hormone production in the 

 host stimulates the growth of the transplanted gland very much. The influence 

 of the hormone consists primarily in an enhancement of the growth processes 

 in the transplant, but in addition there is strong evidence that this factor may 

 favor also the survival of the graft ; and again, as a result of the stimulation 

 of the transplant by the specific hormone, the vascularization of the graft is 

 improved. 



We may add here some related observations concerning the influence of 

 hormones on the transplantation of non-endocrine organs. In our earlier 

 transplantations of the uterus in various stages of the sexual cycle in guinea 

 pigs, we found a favorable effect of hormones given off by the host on the 

 survival of the transplanted decidual cells. Jacobson, in autotransplanting the 

 endometrium of rabbits into the pelvic cavity, observed that the different 

 periods of the sexual cycle in the animal may affect favorably or unfavorably 

 the fate of the transplant and that ovariectomy carried out at the time of the 

 transplantation does not prevent the formation of endometrial cysts, but that 

 it diminishes the size of the cysts and the thickness of their walls. Neumann 

 noted that intra-peritoneal autotransplantation of endometrium succeeds if 

 the animals possess their own ovaries, but that it is unsuccessful in previously 

 ovariectomized rabbits, which indicates that the atrophic uterine mucosa can- 

 not maintain itself in the host. Likewise, while transplantation of the uterine 

 mucosa into sisters is successful, it does not succeed in brothers for the same 

 reason. In these experiments we have to deal chiefly with autotransplantation. 



Corresponding investigations concerning autotransplantation of the Fal- 



