The Significance of the Blood Content of the Bergen A4 Mouse Ascites Carcinoma

THE blood content of ascitic tumours had received only fleeting attention until 1961 when the present author started to investigate the possible significance of the blood content of the Ehrlich ascites carcinoma (Hartveit, 1961b). The conclusion reached from these investigations was that the blood that appeared in the tumour was a reflection of the mouse's response to the injection of homologous tissue (i.e. tissue of the same species but of different genetic make-up from the host). Although the tissue injected was tumour tissue, it could not be concluded that the blood appeared in response to the injection of tumour tissue, but only to tissue that differed genetically from the host. In view of the present controversy as to the existence or non-existence of tumour specific antigens, which is of fundamental importance in the field of tumour immunity, it was felt that an attempt should be made to go deeper into the question of whether the blood that appeared in response to the intraperitoneal injection of the Ehrlich ascites carcinoma appeared because the tumour is a homograft or because it is a tumour