Die Untersuchungen über die Krebsvererbung mittels der Methode der Impetumoren

Summary

• 1. Investigating the heredity of cancer according to the method of transplanted tumours all the variations in their comportment are ascribed to differences in the genes and thence conclusions are made as to the number of genes in the heredity of cancer. The author considers these conclusions as erroneous, because the mentioned differences in the comportment of the transplanted tumours are not accompanied with changes of the genes.

• 2. According to the author after several passages the differences in the comportment of the transplanted tumours do not represent mutations, but durable modifications in the sense ofJollos.

• 3. The reasons of the durable modifications of the transplanted tumours lie in the immunity forces of the organism. Two spontaneous as well as two transplanted tumours upon the same animal, compete for securing a positive growth factor, produced by the organism, in the sense ofEhrlich's theory for theatreptic immunity. Through such a competition there can be achieved a durable modification of the tumours, which resembles mutations.