Abstract
It is commonly believed that the bacteriolytic or biochemical actions of bacteriophage are performed upon specific bacterial species. The possibility of bacteriophage actions on cancer cell, accordingly, seems not to be generally accepted at present. However, recently some authors have reported on the relation between bacteriophage and cell of highly differentiated organism. We surmised that it was necessary to make clear whether a certain phage may act upon the cancer cell or not. The phage used was Escherichia coli 06 and was injected repeatedly into the peritoneal cavity of mouse with Ehrlich's ascites tumor. The light and electron-microscopic observation revealed that intact phage particles were found in cancer cells especially in their cytoplasm where remarkable changes had occurred. The particles were located mainly within the smooth and rough surfaced endoplasmic reticulum.
