Endemic pneumonia virus isolated from malignant lymphoma induced in Swiss mice by 9,10-dimethyl-1,2-benzanthracene.

which authors claim to have shown tumor virus activity in tumors induced by chemical carcino gens (13, 14, 16). Peacock (17) has criticized the work of McIntosh and Selbie (14) on the basis of morphological changes in the tumors which be came filtrable and the fact that in some cases the filtrable tumor arose at a site distant from the irn plantation of the carcinogen. He concludes that only one of these tumors could be accepted as a virus-transmissible sarcoma derived from a tar sarcoma of apparently similar histology. The case reported by Oberling and Guerin (16) was a spindle-cell sarcoma arising in the leg of a chicken 32 months after the injection of methylcholan threne at the same site. This tumor was trans