1894.] The Parasitic Protozoa Found in Cancerous Diseases. 313 
been established between the malignant parasite of cancer and 
certain epithelial and mesoblastic tissues. These tissues are ex- 
cited to enormous overgrowth by the presence of the parasites, whilst 
the tissues with which they have not established a symbiosis are in- 
vaded, devoured and destroyed. Mr. Jackson Clarke thus de- 
scribes the process: “The amceboid parasites make their way 
between the epithelial cells and pass in vast numbers into the 
connective tissue spaces beyond the epithelial part of the 
growth. In their passage they cause the rows of epithelial 
cells to separate, and thus bring about a multiplication of the 
points of epithelial ingrowth and detachments of small groups 
of epithelial cells. A considerable amount of inflammation is 
caused by the invasion of the vascular tissues by the amæbæ, 
with the same result as that seen in inflammatory papillo- 
mata; an extension of epithelial growth, and a formation of 
new blood-vessels. Most of the amcebe disappear, but a small 
proportion enter epithelial cells, where, even in the non-nucle- 
ated stage, they could be detected,” and the evil cycle is car- 
ried on. >- 
Messrs Ruffer and Walker, the first pathologists who demon- 
strated the existence of the cancer parasite in England, state 
that they found a mixture of Foll’s solution, with 1 per cent. 
of osmic acid, gave the most satisfactory results as a hardening 
reagent,’ especiallyin d ting thei nuclear parasites. 
Biondi’s mixture as a coloring agent brings out the organisms 
with all the clearness that can be desired. The “ coccidia, 
stained a light blue, enclose a dark brown nucleus, the can- 
cerous cell is stained a dirty yellow white, while its nucleus 
takes a green tint” [Metschnikoff ]. 
Metschnikoff is of opinion than the coccidiosis of the rabbit 
is a miasmatic disease of the most typical kind, and that car- 
cinomata also approximate to the category of miasmatic affec- 
tions. “Although less pronounced than malaria or goitre,” he 
observes, “the endemic character of cancer is a fact that has 
often struck observers. The frequency of these malignant tu- 
mors is far from being the same in all countries. By the side 
ê Second Note on Parasitic Protozoa in Cancerous Tumors. 2. Medical Journal, 
Nov. 5, 1892. 
