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DISEASES OF THE DIGESTIVE APPARATUS. 



precisely similar to tubercles or small tumors, contain a yellow, 

 thick, creamy, clotted, or caseous mass, which upon microscopic 

 examination is shown to be constituted by encysted oviform cocci- 

 dia, epithelial cells that have undergone fatty degeneration, free 

 nucleus, fat-drops, etc. ; they are separated from the hepatic paren- 

 chyma by a thick connective-tissue shell, composed of numerous 

 nuclei and fibres couceutrically disposed ; they are developed at 

 the expense of several parallel biliary canals; they are, indeed, 

 confluent and dilated biliary canals (Leuckart). 



The coccidia of the intestinal canal have been found in the rabbit, 

 dog, sheep, pig, cat, chicken, etc. They are imprisoned in epithe- 

 lial cells; they are found isolated or displaced in groups forming 

 little whitish spots, standing in relief upon the mucous membrane, 

 which they often cover up to some extent as a pseudo-membrane. 

 It is in the intestinal villi that the largest number are found ; they 

 are there in the sha2")e of small white points, and overrun also Lieb- 

 erkuhn's glands. The presence of coccidia occasions destruction 

 of the epithelium, infiltration of the mucous membrane, even its 

 ulceration, and inflammation of the submucous connective tissue. 



Symptoms. Coccidiosis of the rabbit, which frequently destroys 

 whole warrens, is usually announced, according to Rolofl", by a 

 diminution of the appetite, by icterus, weakness, emaciation, an 

 exhausting diarrhea, tympanites, a staggering or uncertain gait, 

 etc. Death takes place in convulsions. Very often, however, no 

 really appreciable symptoms are observed, notwithstanding the ex- 

 istence of a large number of coccidia ; but in these instances the 

 organic molecular transformations seem to be profoundly altered, 

 , for, according to Cohnheim, irritation of the fourth ventricle does 

 not produce diabetes in a rabbit aflected with coccidiosis. 



In calves that have just been weaned we may observe a fatal 

 dysentery produced by intestinal coccidiosis (Proger). Rivolta has 

 found rabiform attacks in the dog caused by the invasion of the 

 intestinal mucous membrane by coccidia (?). 



Differential diagnosis. Hake, who discovered these parasites, 

 mistook them for pus corpuscles ; Lang considered them as neo- 

 formations. A frequent error is to confound the encysted coccidia 

 with the eggs of the linguatulas, taenias, and nematodes. They 

 have not always been distinguished from the utricles of Miescher 

 (sarcosporidia) ; we shall, however, return to this subject in the 

 article on Diseases of Muscles. We shall also examine further the 



