192 PATHOLOGY 



of the Anopheles mosquito, in whose body the parasite 

 passes through its sexual cycle of development. In 

 the red blood-corpuscles of the warm-blooded host an 

 asexual cycle of development takes place, each parasite 

 developing into fifteen to twenty spores or daughter- 

 cells, the chills and fever characteristic of the disease 

 being coincident with the maturing and scattering into 

 the blood of these daughter-cells. After several genera- 

 tions, sexual forms are developed, which, however, are 

 incapable of fertilization in the blood. When the blood 

 enters the stomach of the mosquito the male elements 

 fertilize the female elements, which enter the walls of the 

 stomach and give birth to a swarm of the asexual form 

 of the parasite. Numbers of these gather in the veneno- 

 salivary glands and are injected into man when the 

 mosquito feeds upon him. 



Morbid Anatomy. The morbid alterations are the 

 result of the disintegration of the red blood-corpuscles, 

 the accumulation of pigment thus formed, and possibly 

 to the development of a toxin. The spleen is enlarged 

 and there may be parenchymatous degeneration of the 

 kidneys. The liver is enlarged and turbid. Anemia 

 rapidly develops, with a lowering of the hemoglobin. 



Morbid Physiology. The chill, fever, and sweating 

 are the result of the changes in the blood, which takes 

 place with the maturing of the parasites within the red 

 corpuscles, which are rapidly destroyed thereby. 



