174 SPOROZOA. 



Crystallospora, Labbe, 1896, p. 554 ; 1899, p. 63. 



Goussia, Labbe, 1896, p. 551 ; 1899, pp. 63-5. 



Eimeria, Labbe, 1899, pp. 58-9. 



Paracoccidium, Laveran & Mesnil, 1902 6, p. 858. 



Eimeria, Castellani & Chalmers, 1919, pp. 475-6 ; Dobell, 1919 a, 

 pp. 147-97 ; Snijders, 1920, pp. 427-32 ; Dobell, 1922, pp. 1498-9. 



Jarrina, Leger & Hesse, 1922, pp. 74-7. 



Eimeria, Craig, 1926, pp. 353-8 ; Thomson & Robertson, 1926, 

 pp. 282-3; 1926 a, pp. 420-1; Wenyon, 1926, pp. 828-62; 

 Knowles, 1928, pp. 358-66 ; Reichenow, 1929, pp. 937-55 ; 

 Kudo, 1931, pp. 271-4 ; Stiles, 1929, p. 881 ; Levine & Becker, 

 1933, pp. 83-106 ; Calkins, 1933, pp. 403, 565 ; Hoare, 1933, 

 pp. 374-7, 378, 381, 383, 385 ; Wenrich, 1935, pp. 7-9 ; Ray & 

 Das-Gupta, 1936, p. 345-6 ; 1937 d, pp. 275-7. 



Oocyst develops four sporocysts, each containing two 

 sporozoites. 



Remarks. — ^The typical life-history is as described by 

 Schaudinn for E. schubergi, of which a brief summary is given 

 for ready reference. Oocysts gain entrance into the host 

 through the mouth. Sporozoites escape from the sporocysts 

 and, passing through the micropyle of the oocyst, move about 

 in the lumen of the gut till they enter the epithelial cells 

 of the gut- wall, where they grow into schizonts. Schizonts 

 are large rounded bodies, which give rise to merozoites. 

 The latter escape into the lumen of the gut and enter new 

 host-cells and repeat the process. Some merozoites develop 

 into macro- and microgametocytes. The macrogametocyte 

 produces a single macrogamete after extruding part of its 

 nuclear material. The microgametocyte produces a number 

 of biflagellate microgametes. Sjmgamy takes place and the 

 zygote secretes a membrane around itself, forming an oocyst. 

 The nucleus divides twice and four sporoblasts are developed 

 inside the oocyst. Each sporoblast secretes a membrane 

 and becomes a sporocyst, and two sporozoites are developed 

 inside each sporocyst. Oocysts pass out in the faecal matter 

 of the host and infect other hosts by being ingested. 



The genus has a very wide distribution, numerous species 

 having been described from all classes of Vertebrates, terrestrial, 

 freshwater, and marine, and a few Invertebrates" (myriopods, 

 etc.). They have been found to occur as intestinal parasites 

 in man, horses, cattle, pigs, sheep and goats, rats and rabbits 

 domestic birds such as fowls, ducks, pigeons, pheasants, etc. 

 a few lizards and tortoises ; in frogs, newts, and salamanders 

 in fish ; in centipedes, etc. According to Levine and Becker 

 (1933) no less than 220 species of this genus have been recorded 

 from 183 species of hosts of widely different groups. These 

 hosts include Annelids, 2 species ; Myriapods, 6 species ; 

 Insects, 3 species ; Enteropneusta, 1 species ; Fishes, 43 

 species ; Amphibia, 10 species ; Reptiles, 26 species ; Birds, 

 24 species ; and Mammals, 60 species. The shape, dimensions, 



