MALARIA AND ITS TRANSMISSION 17 



passed from the region of conjecture to that of 

 fact." 



Malaria. — Malaria is a widely distributed disease 

 prevalent to a greater or less degree on every conti- 

 nent, in parts where there is an average summer 



Fig. 1. To illustrate detection of malaria parasite, a, normal, unparasitized red blood 

 corpuscle ; b, young intracorpuscular parasite ; c, signet ring ; d, intracorpuscular crescent ; 

 e, free female crescent ; /, free male or hyaline crescent ; g, female oval. 



temperature of not less than 6o° F., and while not 

 restricted to the lowlands, does not occur abundantly 

 in high altitudes. The disease is known to occur 

 endemically in Java, Madagascar, and elsewhere at 

 an elevation of 3000 feet. 



Malaria symptoms, even though very slight, are 

 usually manifested in the form of a paroxysm con- 



