A . Herbut and William

phy's finding of 1914 (18), she inoculated irradiat ed rats and mice subcutaneously with minced cell suspensions of human tumors and obtained active growth for two generations or more in 83 out of 100 tumors transplanted. In 1958 she recorded 90 per cent of 101 human tumors surviving and pro liferating for 1@—@0 days in irradiated and/or cor tisone-treated rats inoculated subcutaneously and in hamsters inoculated in the cheek pouch (20). By 1955 (21, 22), out of a group of over 1,000 hu man tumors transplanted, she reported that three epidermoid carcinomas, a soft tissue sarcoma, and an embryonal rhabdomyosarcoma were being propagated with regularity and, in one instance, in such quantity as to produce as much as 3 pounds of tumor a week. Employing similar or slightly modified proce dures, Sommers et al. (18) in 1952 reported 40 out of 75 human tumors surviving in irradiated rats and 30 out of 65 human tumors surviving in treat ed or nontreated hamsters; Hoch-Ligeti and HsU (6) in 1958 recorded successful transplantation of eight out of nine tumors in cortisone-treated rats; Patterson et al. (15) in 1954 reported survival and/ or growth in 23 out of 33 tumors in cortisone treated hamsters with one case of muco-epidermoid carcinoma of the parotid gland surviving 9 months and, at the time, being maintained in the sixteenth generation; and Patterson (14) in 1955 stated that out of 80 malignant human tumors eight were being maintained by serial passage. Because of the enthusiastic reports quoted above, we undertook the heterologous transplan tation of human tumors with the thought of ulti mately using successfully propagated growths in experimental chemotherapy. Since our results di.f fer quantitatively somewhat from those of other investigators we consider our findings worthy of publication.