The discovery of the parasite of carcinoma, like the appearance of the sea serpent, has become an almost perennial occurrence during the past few years. The peculiar cell inclusions, which are not infrequently found in malignant neoplasms of epithelial origin, have passed through almost as many aliases as an habitual criminal. They have been classed as protozoa, as blastomycetes, and as rhizopods, and now we are asked to believe that they are plasmodiophoræ. There can be little question, judging from the photographs and plates which illustrate the various articles which describe them, that the same bodies have been described by different observers under the various names mentioned above. The latest contribution to the literature of cancer parasites comes from Robertson and Wade,1 who, following in the footsteps of Behla and Gaylord, compare carcinoma with the peculiar disease of plant roots called clumps, and claim to have isolated from carcinomata