BABESIA. 



309 



form passes through a series of stages before division takes 

 place. The organism becomes romided, the vacuole first 

 enlarges, then disappears, and the string of chromatin granules 

 is withdrawn into the larger granule (fig. 150, A-G). It now 

 passes through an amoeboid phase, ajid division of the organism 

 is initiated by the separation from the larger granule of 

 chromatin of a smaller one, which remains connected with the 

 larger by a string of granules. The smaller granule divides into 





Fig. 151. — Babesia canis, development in the tick (x c. 1500). 

 A, globular forms in the stomach of the tick ; B, globular 

 form showing split ; C, club-shaped forms ; D, " zygote," 

 which passes through the stomach-wall ; E-H, globular 

 body in ovum or tissue-cells, which shows multiple fission ; 

 I, sporoblasts ; J, formation of sporozoites ; K, sporozoites 

 in the salivary glands. (From Nuttall, after Christophers.) 



two, and the cytoplasm forms two buds, each containing 

 one of these granules ; thus finally a trilobed form results, 

 in which the three chromatin granules are connected with 

 a Y-shaped or V-shaped chromatin strand (fig. 150, D-G). 



