MICROBIAL DISEASES OF MAN AND DOMESTIC ANIMALS 891 



body of the person from whom blood is being sucked. The entry of a sporozoite 

 into a red cell recommences the cycle of development which has just been 

 described. If the adult sexual parasites are not taken up by a mosquito they die 

 off in the blood, but some of the female forms may live for years and then divide 

 parthenogenetically, without a precedent fertilization, to produce several young 



QjsrH'tA 

 SCHIZOCONY (Asexual Generation) ^jftfo 



in MAN. 















r, 

 Q 



Merozoites 



Macrotfamete($) (^Microyamete 



Sporozoites. 



SPOROGONY (Sexual Generation) 

 in the MOSQUITO 



Oocyst with Sporo blasts. 



Oocyst. 



*S&[ Zyyote or 



vermiculc. 



FIG. 189. Diagram illustrating the human and mosquito cycles of existence of 

 the malaria parasite. (After Martin's General Pathology.) 



parasites. It has been suggested but never demonstrated that the sporozoites 

 may enter eggs lying in the ovaries of infected mosquitoes and that mosquitoes, 

 hatched from such eggs, may inherit the infection from their parent and that 

 they, also, are able to transmit malaria. 



In fresh preparations of blood, a malarial parasite is seen as a body of varying 

 size, which is more refractile and of a lighter color, than the red cell which contains 

 it. In its growing phase it has distinct amoeboid movement and the pigment 

 granules lying in it are in active motion. In preparations, stained by a modification 

 of Romanowsky's method, every malarial parasite is seen to possess a definite purple 

 nucleus surrounded by blue-staining cytoplasm. Young parasites measure less 



