532 



NEOSPORIDIA] 



gested that the parasite may be transmitted by the larvae and 

 imagines of the blow-fiy (Calliphora) or the flesh-fly (Sarcophaga). v... 



It is true that Smith has infected (after a long incubation) mice 

 by feeding them on the flesh of infected mice, but that, of course, 

 might simply be by the merozoites, and would in any case not 

 explain how herbivorous animals are infected. Our feeding experi- 

 ments v\rith a dog Were not successful. 



Erdmann says that the spore germinates in the intestine of the 

 host, and liberating the toxin — sarcocystin — which may come from 

 the polar capsule, causes the epithelium to be shed, while the little 

 amoeba coming out from the spore is able to penetrate the denuded 

 area and to get into the lymph spaces of the intestine, Where it lives 

 about a month and then passes on to the muscles. 



Crawley considers that the spore bores its way into the intestinal 

 cells where it appears to undergo some form of schizogony. At all 

 events, it disappears in twenty-four hours, but later he thought that 

 he had noted sexual differentiation in these spores in the cells, 

 and the formation of a zygote. 



Pathogenicity. — Sarcocystis tenellcB hubali is very common in the 

 buffalo-meat in Ceylon, and frequently causes inquiries to be made. 

 It appears as white particles, called by the native butchers ' milk 

 nerves,' lying among the muscular fibres of tongue, larynx, 

 diaphragm, and skeletal muscles. This ingestion of infected meat 

 has apparently no deleterious effect on man, but the spores may be 

 the cause of irregular fever. 



Classification. — A number of species are recognized : — 



1. Sarcocystis mieschenana Kiihn, 1865, found in the pig. 



2. 5. bevtrami Dofiein, 1901, in the horse. 



3.5. tenellcB Railliet, 1886, in the sheep. S. tenellcs buhali, in the Ceylon 

 buffalo. Vuiilemin has described a case of this infection in man. 



4. S. blanchardi Doflein, 1901, in cattle. 



5. 5. lindemanni Rivolta, 1878. — This species has been found in man. 

 They were first described indefinitely by Lindemann in 1868, in the myo- 

 cardium and on the valves of the heart of a person who had died of dropsy. 

 They were said to be 3 millimetres in length and 1-5 millimetres in breadth, 

 but it is very doubtful what these really were. 



Rosenberg, in 1902, reports a most doubtful case of a cyst in a papillary- 

 muscle in a person who died from pleuritis and endocarditis. Kartulis 

 described them in the muscular system and liver (most doubtful) of a person 

 who died from multiple abscesses in the liver and muscles. The man was a 

 Sudanese. Koch, in 1887, described an undoubted case in Egypt. 



Baraban and St. Remy, in 1894, described them in the laryngeal muscles 

 of a man who had been executed. This description is not to be doubted. 

 The parasite is described as being 1*6 millimetres long, and about 0-17 milli- 

 metre in width. Vuiilemin in Nancy and Darling (1909) in Barbados have 

 recorded cases. 



6. 5. hueti Blanchard, 1885, in the seal. 



7. 5. kortei Castellani and Chalmers, 1909. — This parasite, found by Korte 

 i n the thigh muscles of Macacus rhesus, is peculiar in that the inner coat was 

 not continued into the cytoplasm of the trophozoite, and the endoplasm 

 contained only gymnospores (merozoites), and no pansporoblasts or alveolar 

 network. The spores contained nothing but a nucleus, no cell membrane 

 or other structure being visible. There were no signs of any reaction on the 

 part of the tissues. 



