Chapter 2 

 Heredity and Transplantation of Tumors 



In the preceding chapter it has been shown that the results of autogenous, 

 homoiogenous and heterogenous transplantations of tumors differ great- 

 ly and that the differences are very similar to those found in correspond- 

 ing transplantations of normal tissues. In both tumors and normal tissues the 

 organismal differentials are identical, or almost identical, in host and graft 

 in case of autotransplantation ; they are different in case of homoiotransplanta- 

 tion, and still more unlike in case of heterotransplantation. While these inves- 

 tigations have established, in a definite way, the importance of organismal 

 differentials, and therefore also of heredity in the transplantation of tumors, 

 there were already some earlier observations which pointed to the significance 

 of constitutional hereditary factors. Thus Morau, in his transplantations of 

 mouse carcinoma, believed that in the offspring of mice in which the tumors 

 could be transplanted successfully, the chances for the growth of the trans- 

 planted tumor were better than in not directly related mice. At an early 

 stage in our first series of transplantations of rat sarcoma, we found that this 

 tumor did not grow in a strange species, even in one nearly related to the rat ; 

 neither did it grow in some white rats; but it did grow in a hybrid between 

 a gray and a white rat. At that time we decided, therefore, to study the finer 

 differences within white rats which determine their suitability or lack of 

 suitability as hosts for these tumors. The presence of a constitutional element 

 in tumor transplantation was also indicted by our observations that in the 

 same individual in the case of multiple simultaneous transplantations of the 

 same kind of tumor, either all or none of them took ; and that if a transplanted 

 tissue did not take in an individual rat, subsequent transplantations proved 

 usually likewise negative, although some exceptions to this rule occurred, in- 

 dicating that certain accidental, variable factors complicated these experi- 

 ments. Similar observations were made by Jensen in his serial transplanta- 

 tions of mouse carcinoma. Subsequently, Michaelis, as well as Bashford and 

 Murray and others, found that white mice obtained from different localities 

 differed in the number of takes which followed inoculation with mouse car- 

 cinoma. In the meantime, we had successfully transplanted a carcinoma, origi- 

 nating in a Japanese waltzing mouse, in about 100% of all Japanese waltzers, 

 although the growth in the first generation of transplants was slow. This 

 indicated that here we had to deal with a very favorable soil of a homozygous 

 character. A few years later, Tyzzer (1909) studied the differences in the 

 number of takes of another carcinoma, which had developed spontaneously 

 in a Japanese waltzing mouse, after transplantation into Japanese, into com- 

 mon white mice, and into hybrids between these two species or subspecies. 

 Tyzzer expressed the view that hereditary factors determine the differences in 



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