224 COCCIDIUM OVIFORME. 



and scattered in groups, so that they looked as if embedded in the sur- 

 rounding connective tissue. Since the contents of the Coccidia were 

 quite clear, as is always the case in preparations mounted in glycerine, 

 the bodies might easily have been mistaken for eggs of Distomum (D. 

 lanceolatum), but in my further examination any doubt as to their 

 true nature was wholly removed. 



The other case was based on a preparation from v. Sommering's 

 collection annexed to the Pathological Institute in Giessen. It showed 

 ulceration of the bile-ducts, in which Coccidia were to be seen. The 

 label bore the words, " An Distomis orta" which perhaps originally 

 read " Distomatis ova." 



But it is not only the liver, but also the intestinal canal, which is 

 invaded by these parasites, and to a greater or less extent affected by 

 them. We know cases, apart in the meantime from man, where not only 

 rabbits, dogs, and cats, but also other mammals sheep, pigs, guinea- 

 pigs, and moles were infested with these intestinal Coccidia. Those of 

 the mouse and others belong, as we have noted, to a distinct species. 

 The same is true of the Psorospermice of fowls, 1 ducks, and geese, 

 which, according to a preparation kindly lent me by Professor Ziirn, differ 

 from mammalian Coccidia in their spherical form, in the thinness of 

 of their shell, and in their smaller size (0'002 mm. in diameter), but 

 agree with them (according to Eivolta) in their life-history. I have 

 myself only studied the intestinal Coccidia of the dog and the cat. 

 In the case of the latter, I could most distinctly convince myself that 

 the Coccidia were contained in the epithelial cells until perfectly ripe. 

 This is much more easily demonstrated than in the case of the hepatic 

 Coccidia, for the intestinal epithelial cells, perhaps because of their 

 opercular structure, have a greater permanency of form, and remain 

 closed even when abundantly infected. 



In the milder cases the Coccidia are sometimes scattered, some- 

 times arranged in groups. In the latter case one can recognise the 

 infected places even with the naked eye as somewhat elevated whitish 

 spots of varying size. There are also cases in which the surface of the 

 intestine is uniformly infected and considerably swollen, so that it looks 

 as though it were overlaid with a false membrane. I found it thus, 

 particularly in a dog which had served for an experiment with Trichina* 

 The parasites are usually most crowded in the villi, which then 

 appear like little white points, as after an absorption of chyle, so that 

 it has even been conjectured that the Coccidia of course, as normal 

 structures might play some part in the absorption of fat. 3 The 



1 The occurrence of Psorospermice in birds was first observed by Rivolta (1869). 



2 In another dog infected with Trichina I found numerous Coccidia in the intestine : 

 Virchow has also made the same observation. 



a Finck, "Sur la physiologic de 1'epithelium intestinale," These Strassbourg, p. 17, 1854. 



