The Excretion of Calcium and Magnesium. 



i3 



was kept for signs of retarded development or retrogression in the 

 tumors thus brought under the continued influence of blood from 

 a resistant animal, but no alteration of the sort was observed. The 

 growths extended with the same rapidity as those in control ani- 

 mals. The findings are against the presence in circulation of 

 destructive antibodies for cancer. 



The Flexner-Jobling adeno-carcinoma was the tumor employed. 

 Animals were selected which bore in the subcutaneous tissue of 

 one side a vigorous growth 1 to 3 centimeters in diameter. Some 

 were kept as controls and others placed in parabiosis with resistant 

 rats. These latter had failed on three successive implantations to 

 develop a tumor. The appearance in most of them of a small 

 retrogressing nodule after the first implantation, and the complete 

 absence of such a nodule after the later ones pointed to an acquired 

 immunity in addition to the natural resistance. Experiments with 

 rats of high acquired immunity are now under way. 



Sauerbruch and Heyde found that for the healing together of 

 rabbits or dogs it is imperative that they be young and of the 

 same litter. Even then they did not endure the union for more 

 than two weeks, one succumbing within that time to a cachexia, 

 incident, it is supposed, to the new metabolic relation. My obser- 

 vations show that white rats tolerate much better the conditions 

 of union. Adult animals of different litters will heal together per 

 primum and live in parabiosis as long as thirty-four days. Evi- 

 dently those tissue distinctions between individuals based on 

 parentage and age are much less marked in white rats than in 

 some other species. 



9 (419) 



The excretion of calcium and magnesium after 

 parathyroide ctomy . 



By JEAN V. COOKE. (By invitation.) 



[From the Carnegie Laboratory , University and Bellevue Hospital 



Medical College.^ 



The brains of dogs dying with parathyroid tetany contain a 

 slightly greater amount of calcium than do those of normal dogs, 

 which would indicate that a decreased calcium content of the brain 

 is not constant in tetany. The magnesium content of the brain is 



