A GREAT deal of research work has been done in an effort to find a way of treating cancer biologically by nondestructive methods, i. e., methods other than surgical intervention and irradiation. Early experimenters attempted to induce resistance in laboratory animals by inoculation with material from tumors. Ehrlich,1 Lewin,2 Képinow3 and Koenigsfeld4 reported successful results; however, Hertwig and Poll,5 Borrel,6 Gierke,7 Fränkel and Fürer8 and Wood9 were unable to induce any resistance in their experimental animals. Since the different investigators did not use the same method of treatment, it is difficult to compare their results and to draw definite conclusions.
Almost coincidental with the work on the immunization of animals by tumor inoculations were investigations of the immunizing power of tissues other than neoplasms. Many tissues were used, but of particular interest in this paper are spleen and liver.