1110 PATHOG U N 1 C PK( >T< >Z( ) A 



may lie free in the plasma. Unlike the schizonts, the gamctocytcs 

 have the pigment uniformly distributed throughout the body and 

 there is no indication of segmentation. The young sporonts are 

 distinguished from schizonts by the absence of the vacuole, and, 

 when a little older, by a larger amount of hemozoin. 



Flasmodium malarias. The quartan parasite has a life cycle of 

 seventy-two hours, or twenty-four hours longer than the tertian, and 

 the paroxysms come on every third day, or, according to the Italian 

 method of reckoning time, on the fourth day. The young rings of 

 the plasmodium mala-rice are indistinguishable from young tertian 

 rings, but the diagnosis may be made on older forms. The bleach- 



FIG. 155. PLASMODIUM M A L A"R i m . FIG. 156 PLASMODIUM MALARLE. (Army 

 (Army Med. School Collection, Wash- Med. School Collection, Washington, 



ington, D. C.) D. C.) 



ing, enlargement and stippling of the erythrocyte character- 

 istic of tertian is never found in quartan fever, the infected ery- 

 throcyte being almost normal in appearance. The well-grown 

 quartan parasite does not show amoebic changes but assumes a band 

 form, more or less wide, stretching across the red cell from border 

 to border; with increasing age the band widens until the parasite 

 is nearly square and the hemozoin accumulates toward the center. 

 Segmentation gives rise to almost symmetrical "daisy" forms, show- 

 ing six to eight or, rarely, fourteen merozoites. Parasites of dif- 

 ferent ages may be found, as in tertian, and it is characteristic of 

 quartan fever that examples of all stages of the life cycle may be 

 found at the proper time in the peripheral circulation. Gametocytes 

 differ from tertian mainly in size, since they are never larger than 



