202 COCCIDIUM. 



because the infection might have taken place in some other way. 

 Manz asserted his conviction that the digestive juice had a destructive 

 effect on the tubes ; and having used some for feeding an animal, he 

 could find, after a few hours, only their remains in the gastric con- 

 tents ; nor was there a trace of them in the intestinal wall or in the 

 muscles. 



Although the tubes occasionally occur in immense numbers close 

 to one another, so that the flesh looks as if half of it consisted of 

 Psorospenu-tubes, yet they seem usually to cause no special uneasi- 

 ness. In many cases, however, the phenomena of paraplegia, retarded 

 respiration, and even suffocation, are observed as associated with the 

 presence of the tubes, and may with some probability be referred to 

 this cause (Damann, Leisering, v. Niederhausern). 



These parasites have, however, no bearing on human pathology, 

 for in spite of their frequency and wide distribution (not even the 

 common fowl being exempt), they have never as yet been found in 

 man. Even the eating of flesh containing Psorosperms in abundance 

 has hitherto always proved harmless. 



Having become somewhat familiar, through the foregoing informa- 

 tion, with the general structure and life-history of the parasites be- 

 longing to the Sporozoa, it is time to become acquainted more in detail 

 with the occurrence of these creatures in man. We shall therefore 

 turn to the consideration of the so-called " egg-shaped Psoroperm," of 

 which mention has already been made. 



COCCIDIITM, Leuckart. 



Kloss, "Ueber Parasiten in der Niere von Helix," Abhandl. d. Senkcnb. Geselhch. 

 Frank/., 1855. 



Eimer, " Ueber die ei- oder kugelformigen sog. Psorospermien der Wirbelthiere." 

 Wuiv,burg, 1870. 



Aime" Schneider, "Note sur la psorospermie du poulpe," Archiv. d. zod. exptr., t. iv. f p. 

 xl., 1875. 



In, their youth, these parasites are naked inhabitants of epithelial 

 cells, but afterwards envelop themselves with a firm shell at the close of 

 their period of growth. In this condition, in which they present a 

 puzzling resemblance to the eggs of certain Entozoa, they quit their former 

 resting-place, and generally the former host also, and transform their 

 substance into a larger or smaller number of spores, each having a granular 

 ball and rod vrithin. The spores themselves have a rather thin wall, and 

 are of a round 01* elliptical shape. 



We have already observed that the Coccidia occur preferably in 

 warm-blooded organisms, and that they sometimes appear in such 



