SAKCOCYSTIS. 363 



Family SARCOCYSTID^ Babudieri, 1932. 

 Genus SARCOCYSTIS Lankester, 1882. 



Sarcocystis, Lankester, 1882, p. 54. 



Sarcocystis -\- Balhiania-\- Miescheria, Blanchard, 1885, p. 244. 



Sarcocystis, Labbe, 1899, pp. 116-19; Minchin, 1903, p. 308 j 

 Minchin, 1912, pp. 419-22 ; Castellani & Chalmers, 1919, 

 pp. 530-3 ; Wenyon, 1926, pp. 760-9 ; Knowles, 1928, 

 pp. 333-7 ; Reichenow, 1929, pp. 1120-7 ; Kudo, 1931, pp. 326-8 ; 

 Calkins, 1933, pp. 555-6 ; Reichenow, 1935, p. 394. 



With the characters of the family. 



The cysts are to be found in practically all body -muscles ; 

 in Ruminants they are found specially in the oesophagus, in 

 other animals in the heart, intercostal or abdominal muscles. 

 The cyst-wall may be produced entirely by the parasite 

 (as in Sarcocystis muris) or in part by the host (as in S. tenella). 

 The cyst is divided into chambers, the peripheral ones containing 

 pansporoblasts or sporoblasts, while the central ones contain 

 mature spores. The mature spores have neither polar capsules 

 nor polar filaments. They show a very granular nucleus, 

 a thin cell-membrane, and many metachromatic granules in the 

 cytoplasm. 



Many species have been recognized as occurring in man, 

 sheep, cattle, horses, rats, and mice on the basis of occurrence 

 in different host- species and shght difference in the dimensions 

 of the spore ; but they are otherwise morphologically indis- 

 tinguishable. 



300. Sarcocystis blanchardi Doflein, 1901. (Fig. 179.) 



Sarcocystis blanchardi, Doflein, 1901, p. 221, figs. 197, 198. 

 "f Sarcocystis tenella, Shipley, 1904, pp. 45-7, pi. i, figs. 10, 17. 

 'f Sarcocystis tenella bubalis, Willey, Chalmers, & Philip, 1904, 



pp. 65-72, figs. 1, 2. 

 'ISarcocystis sp., Chatterjee, 1907, pp. 77-8. 

 Sarcocystis tenella bubali, Wenyon, 1926, p. 768. 

 Sarcocystis blanchardi, Wenyon, 1926, p. 768. 

 Sarcocystis tenella, Wenyon, 1926, pp. 760, 768, fig. 329 ; Knowles,. 



1928, pp. 333-6. 

 Sarcocystis blanchardi, Reichenow, 1929, p. 1123, figs. 1126, 1127 ;, 

 1935, p. 392, fig. 46. 



Cysts somewhat pointed, though not very sharply, at either 

 end, or both ends truncated, the thickest portion being in the 

 middle. The covering of the cyst consists of two sheaths, the 

 outer one being continuous and the inner forming partitions 

 which divide the cyst into a number of polyhedral chambers 

 with granular contents. The peripheral chambers are com- 

 pletely filled with fine granulations and stain deeply. The 

 central chambers are empty or contain spores. Spores are 

 minute crescent-shaped bodies with granular contents. 



Dimensions. — The largest cysts measure 30 mm. in length,, 

 5 mm. in breadth, and 3 mm. in thickness. 



