SPOROZOA 



417 



grows long and rather slender and is differentiated to form either 

 the male or the female gametocyte, readily distinguished by 

 appearance in stained preparations. Meanwhile, the host cell 

 becomes very much elongated and pointed at the ends. The 

 explanation of this peculiar distortion of the cell is unknown, but 

 it may be due to the mechanical streaming of the blood acting 

 upon the bladder-like cell which has been deprived of elasticity 



FIG 187. Diagram of the developmental cycle of Proteosoma. i, Sporozoit 

 entering an erythrocyte; i. 2, 3 and 4, the cycle of schizogony; 5, macrogameto- 

 cyte; 5^, microgametocyte; 6, macrogamete; 6a, formation of microgametes; 7, 

 fertilization; 8, ookinete; 9, formation of sporoblasts (in mosquito); 10, forma- 

 tion of sporozoits; n. sporozoit. (From Doflein after Schaudinn,} 



by the destructive action of the parasite. The further stages in 

 the cycle of sporogony are unknown. An asexual multiplica- 

 tion probably occurs in some internal organs of the bird. Fan- 

 tham has observed schizogony in the spleen of Lagopus scoticus, 

 the red-game grouse of Scotland, infected with a similar parasite 

 Leukocytozoon lovati. 



Proteosoma (Plasmodium) Praecox. Grassi and Feletti de- 

 scribed this malarial parasite of birds and designated it as Hcem- 

 27 



