Abstract
I have found that the Ehrlich ascites tumor cells as well as the Yoshida sarcoma cells can be an adequate host for the propagation or ectromelia virus. These two new host-virus systems have rendered it possible to pursue the morphological changes induced in the tumor cells infected with the virus. As a result we have known that this virus makes it a rule to produce two kinds of inclusions during its life cycle. The one which appears earlier and stains red with Giemsa solution has been named B body, and the other which appears later, stains lilac and contains acidophilic particles in itself has been named A body. The so-called Marchal body has been found nothing but A body. The natures or these two bodies have been compared.
