In the second report of the Cancer Committee to the Surgical Department of the Harvard Medical School,1 are given the results of a number of investigations bearing upon the parasitic theory of the origin of cancer. In the summary of the work given by Edward H. Nichols at the conclusion of the report, the plan of the investigations is made clear. Thus it has been claimed by the adherents of the theory of the parasitic origin of cancer that coccidium oriforme and other protozoa may produce a proliferation of epithelial cells analogous to that of carcinoma. This question was studied by E. E. Tyzzer, who devoted himself to an investigation of coccidium infection of the rabbit's liver. Tyzzer shows that the lesion of coccidium oriforme is essentially a chronic inflammation which in its progress and termination is not at all analogous to that of carcinoma.
It has been claimed