254 



INFECTIOUS entp:ro-hepatitis 



malady is of more than ordinary significance to those engaged 

 in the turkey industry. 



§ 191. Etiology. In 1S95, Smith described a micro- 

 organism belonging to the protozoa which he found to be 

 associated directly with the disease process. He designated it 

 Anucba mdeagridis. In those cases in which the disease was 

 recent, or at its height, the parasites were very numerous in 

 the affected tissues, while in those in which the disease process 

 was far advanced and associated with degenerative or regen- 

 erative changes, the parasites were found with difficulty. 

 The most fre- 







quent appearance pre- 

 sented by the para- 

 sites is that of round 

 homogeneous bodies 

 with a sharply de- 

 fined, si n g 1 e - CO n - 

 toured outline. With- 

 in these bodies and 

 situated some what 

 eccentric ally is a 

 group of very minute 

 granules, prob ably 

 representing a nuclear 



structure. Thev vary 



. ■ . Fig. 63. Aviivba mcleagridis. (/) Iso- 



somewhat m size ^^^^^^ organimis : {2) single parasites; (3) 

 measuring Irom 8 to groiips{a) o/the amwba; in iiuicous inembrane 

 lOj-i in diameter in of a turkey's areum. [Stnilh). 

 some cases, from 12 to i4/( in others. In the fresh tissues 

 they are distinctlj' larger than the parasites within the tissues, 

 which have undergone the hardening process. The latter are 

 from 6 to io/( in diameter. This difference may be due to 

 shrinkage, on the one hand, and on the other to a slight flat- 

 tening of the bodies by pressure in the fresh preparations. 

 These peculiar homogeneous bodies were found, as a rule, free 

 in the crushed preparations, although occasionally giant cells 

 were detected which contained a number of them. The cell 

 nuclei of the 2:iant cells are not visible in the fresh condition. 



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