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Scientific Proceedings (132) 



kept under the same conditions as the tumor animals. The sacri- 

 ficing of these animals was so arranged as to provide control 

 observations on the condition of the glands existing at the time 

 inoculation was carried out as well as at the time of determining: 

 the effect of the inoculation. The results of tumor inoculations 

 were further controlled by the examination of a large series of 

 animals with various forms of spontaneous disease and of ani- 

 mals inoculated with Treponema pallidum as reported else- 

 where. 7 



Some of the experimental animals died as a result of tumor 

 growth while others were either arbitrarily killed at intervals 

 of from 48 hours to 4 weeks after inoculation or at some critical 

 period during the progress of the disease. The results thus ob- 

 tained were analyzed with reference to the growth and the 

 malignancy of the tumor as indicated by the clinical course of 

 the disease and the conditions existing at the time of death. 

 The control animals with other diseases were handled in much 

 the same way. 



RESULTS 



Stated briefly, these investigations showed conclusively that 

 the growth of the tumor was associated with the occurrence of 

 marked alterations in the size and the general appearance of 

 such organs as the thyroid, the thymus, and the suprarenals and 

 that less pronounced changes took place in the parathyroids and 

 the hypophysis. Distinct histological changes also occurred in 

 the thyroid, the thymus, and the hypophysis, but no definite 

 change could be made out in the other glands. 



In general the initial change was of the nature of a hyper- 

 plasia associated at first with a reduction in the weight of the 

 gland which was followed by hypertrophy, or an increase in 

 weight, while the ultimate condition presented depended upon 

 the course of the disease. Thus, where the tumor progressed 

 for a considerable period of time with the formation of 

 metastases, there was a marked increase in the weight of such 

 organs as the thyroid and the suprarenals while the thymus re- 

 mained small or diminished in size. If the disease assumed a 

 highly malignant character as indicated by the early appearance 



7 Brown, W. H., and Pearce, L., Proc. Soc. Exper. Biol, and Med., 1923, 

 xx, 47C. 



