296 



SPOROZOA. 



and form large multinucleate masses or schizonts (Koch's 

 "blue bodies "). They may be discovered by puncture of the 

 enlarged glands. In dried films, stained by Romanowsky's 

 stain, they will be seen as blue masses of cytoplasm with 

 a varying number of red chromatin dots. In films they may 

 be found in the endothelial cells or free, but in sections they 

 are always intracellular. About fourteen days after infection, 

 and simultaneously with the attack of fever, the schizonts 

 may be recognized as of two kinds, some containing a smaller 

 number of larger nuclei and others containing a larger number 



Fig. 144. 



K 



M 



N 



-Theileria parva (Theiler). A-D, stages in the red blood- 

 corpuscles ; E, free schizont ; F, intracellular schizont 

 which gives rise to merozoites ; G, free gametocyte-pro- 

 ducing body ; H, intracellular gametocyte-producing 

 body ; /, yomig gametocytes in a blood-corpuscle ; J, ripe 

 microgamete ; K, ripe macrogamete ; L, zygote : M, ooki- 

 nete ; N, multiplication cysts in the salivary glands of 

 the tick ; 0, free sporozoites. (From Reichenow ; A-D after 

 Theiler's preparations ; E-0, after Gonder. ) 



of smaller nuclei. The former break up into a number of 

 minute bodies (merozoites), which enter other cells, grow, 

 and reproduce by schizogony. The latter give rise to gameto- 

 cytes which enter the blood and penetrate the red corpuscles. 

 These forms in the blood are very small, ring-, comma-, pear- 

 shaped or rod-like ; in the latter the nucleus hes at one end 



