CHAPTER IX 

 PROTOZOA AND DISEASES CAUSED BY PROTOZOA 



Plasmodium Malarias. There are three species of 

 this parasite, each giving rise to a different type of 

 malarial fever: 



The tertian variety, in which the parasite reaches 

 maturity in forty-eight hours, and causes the benign 

 tertian type of the disease. 



The quartan variety, which reaches maturity in seventy- 

 two hours, and causes the benign quartan type of the 

 disease. 



The estivo-autumnal variety, developing to maturity 

 in twenty-four to forty-eight hours, and causing the 

 malignant estivo-autumnal type of the disease. 



The source of infection is the bite of the mosquito, in 

 whom the sexual cycle of development of the parasite 

 occurs. The mosquito can only become infected by 

 sucking the blood of a malarial patient. 



Amoeba Dysenteriae. A protozoon the cause of 

 amebic dysentery. Found in the intestinal ulcers, 

 feces, and secondary liver abscesses of those suffering 

 from the disease. Source of infection is unknown. 



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