MALARIA yy 



Ouinine eiven b\' the mouth verv often does not e^^ldicate the 

 asexual cvcle in the marrow and spleen; the residual parasites become 

 immune; the longer the asexual cycle persists, the easier it acquires 

 immunity against the drug, consequently large doses must be given 

 to eradicate the disease. 



The crescent body of subtertian malarial infections exhibits no 

 amoeboid movements, has a very crescentic shape, contains needle- 

 shaped h^emozoin particles somewhat centrally placed, and shows a 

 thin circular outline of the damaged red cell outside it. 



Rarely twin crescents may be seen within one red cell. These cell 

 membranes are better made out in stained specimens. 



When the crescent is young the hiemozoin particles are scattered. 



When the crescent is mature the ha^mozoin particles are concentric. 



\\^hen the crescent is effete the protoplasm shows vacuolation, e.g., 

 degeneration. 

 ■ The hiemozoin can be dissolved by weak solutions of ammonia. 



in the male the protoplasm is hyaline and the ha?mozoin loosely 

 arranged ; the protoplasm stains more deeply ; the nucleus is larger. 



In the female the protoplasm is faintly granular, the ha?mozoin 

 more concentrated and centrally placed. The protoplasm stains 

 faintly, the nucleus smaller. 



llie early forms seen in the spleen and bone marrow about the 

 fourth day of a subtertian malarial attack are rarely seen in the 

 peripheral blood until they are mature, which is about seven davs later. 



Some of the crescents outside the body become oval or spherical 

 and throw off microgametes like the large spherical parasite; the 

 remaining central portion breaking up is carried awav bv phagocvtes 

 when the microgametes have become separated. 



Just before the filaments are thrown out the agitation of the hyaline 

 sphere becomes intense. These are the male sex cells. 



The granular spheres do not give off these filaments or micro- 

 gametes because they are the female sex cells. 



In the parasites other than the subtertian ones the large spherical 

 parasites act in a similar way, with the exception that they are never 

 crescent-shaped. 



Ross has shown that the blood must come in contact with the air 

 for these changes to take place in the male sex cells. Adding a little 

 moisture will hasten the process. Both of these factors, air and 

 moisture, can be added by gently breathing on the slide before adjust- 

 ing the cover slip, the male sex cells of course being mature. 



THROUGH THE ANOPHELIN^E. 



When mature crescents are taken up by some of the Anophelina?, 

 they become transformed into male or female sex cells, the filaments 



