PAKATHYKOID GLANDS 689 



regression and, at the same time, lively proliferation. Biedl has pub- 

 lished a drawing of such tissue on page 112 of the second edition of his 

 Inner e Sekretion. 



Other investigators have tried transplanting parathyroid gland by in- 

 travascular injection, and assert that the little emboli will grow and func- 

 tion, at least for a time. Thus, Landois (6) made autotransplantations in 

 this way, injecting the external parathyroids (after extirpation of the 

 internal) ; tetany was thus prevented in 7 out of 11 experiments. And 

 Joannovics has also made intravascular isotransplantations of embryonic 

 thyroid and parathyroid tissue in cats ; he found that these isotransplanta- 

 tions would keep the animals alive for some time after total thyropara- 

 thyroidectomy, though they ultimately died of cachexia. 



Implantations of parathyroid glands have also been made in rabbits, 

 rats, and other animals. Cristiani, who has had a large experience with 

 parathyroid transplantations in both rats and cats, states that, notwith- 

 standing central necrosis of the grafts, he found normal parathyroid tis- 

 sue two years after implantation in the rats and five years after implanta,- 

 tion in the cats. 



It would seem from these studies of transplantation of parathyroid 

 glands in animals that the grafts rarely, if ever, develop into fully func- 

 tioning organs. Absorption from the gland substance transplanted can, 

 however, temporarily compensate for parathyroid insufficiency, and, per- 

 haps, give accessory parathyroid glands a chance to hypertrophy, or in- 

 jured parathyroid glands a chance to recuperate. 



Halsted (a) in 1907 described at length his technic for the transplanta- 

 tion of parathyroid glands into the spleen of dogs. He also stated then that 

 the thyroid gland apparatus in Graves' disease in human beings should 

 serve admirably as a site for parathyroid transplantation. On several 

 occasions, when operating for exophthalmic goiter, he transplanted to the 

 opposite lobe, or into the isthmus, a parathyroid gland, the nutrition of 

 which had been cut off or imperilled. Once a parathyroid that had been 

 thus transplanted was subsequently and unintentionally excised. 



Halsted early thought of parathyroid transplantation as a remedy in 

 gastric tetany. When performing a gastro-enterostomy in one such case, 

 he prepared for transplantation of a parathyroid gland into the spleen. 

 Dr. MacCallum and Dr. Sowers obtained parathyroid glands for him from 

 a cadaver (one hour after death). Unfortunately, a little carbolic acid 

 came into contact with these parathyroids before the transplantation could 

 be made, so he desisted from the attempt, though the spleen was in his 

 hand and everything was in readiness for the transplantation. 



In his report, made in 1907, Halsted stated that he had transplanted 

 parathyroids into the thyroid gland and the spleen in seventeen dogs. In 

 the spleen of each of three dogs as many as seven parathyroid glands 

 were transplanted at one time. 



