262 C. CLIFFORD DOBELL. 
discussion has not previously been described, and must hence 
be made a new species. 
With regard to the occurrence of Himeria rane, I can 
record the facts that it was found in Rana temporaria 
(Cambridge and Munich), in ca. 15 per cent. of all frogs 
examined,! and upon a single occasion in Rana esculenta 
(Munich). 
I have always encountered the stages of the sporogony of 
this organism in the lower end of the frog’s gut—about the 
posterior half of the small intestine, together with the large 
intestine. Although I have cut a large number of sections — 
and made repeated examinations of the epithelium of the 
small intestine and the liver, both in frogs containing spores 
and in those apparently uninfected, I have never succeeded 
in finding the slightest trace of the schizogony. I have also 
examined the kidneys without result, but the distribution of 
the spores seems to exclude the possibility of these being the 
seat of schizogony. It appears most probable that schizogony 
takes place in the smal! intestine—in the upper part—and is 
completed before any of the parasites proceed to spore 
formation. Hence the presence of oocysts in the rectum 
indicates that schizogony is finished. 
Sporogony.—l have been able to follow the whole of the 
sporogony of this coccidian in the living animal. I have 
completely failed to obtain stained preparations at any stage, 
owing to the extraordinary impermeability of the oocysts and 
spores. Every method has proved unavailing. Even the 
methods which I have found successful in other cases— 
dilute acid Delafield’s hematoxylin, acid alcoholic carmine, 
etc.—have quite failed in this case. I have left the oocysts, 
etc. in these stains for over two months without any staming 
whatsoever taking place. The following is the series of 
stages to be seen in the living organisms: 
The earliest stage found is that shown in Pl. 5, fig. 92. 
The oocyst is already well developed, and the contents of the 
cyst are seen to consist of a dense mass of very highly 
1 But it occurs more frequently in the Cambridge frogs. 
