246 ANIMAL PARASITES 



outbreak of chills and fever, various clinical names have been 

 given to the manifestation of the disease. Mannaberg has 

 arranged the following scheme to show the different forms of 

 outbreaks. The numbers apply to the paroxysms. Each 

 developmental cycle is numbered alike: 



i i i i i i i. Simple quotidian fever. 



I o i o i o i Simple tertian fever. 



looiooiooi. Simple quartan fever. 



12121212. Double tertian fever. (Two infections.) 



.123123123. Triple quartan fever. (Three infections.) 



120120120. Double quartan fever. (Two infections.) 



The figures refer to days on which paroxysms of fever occur. 

 The o represents the afebrile day. 



PLASMODIUM MALARIA (Laveran) 



This is the quartan parasite, and produces in man, in cases of 

 one infection, paroxysms of fever every fourth day. 



It appears in the blood, after a paroxysm, as a small non-pig- 

 mented body on the bodies of the red blood cells. It has feeble 

 amoeboid motion; slowly penetrates the corpuscle, and specks of 

 melanin appear in its protoplasm. Forty-eight hours after the 

 attack the parasite measures from one-half to two-thirds the 

 size of the red cell. Sixty hours after the paroxysm twelve 

 before the next the parasite completely fills the red cell, leav- 

 ing x only a narrow rim, which later on disappears. Six hours 

 before the next paroxysm, shizogony begins. The grains of 

 melanin are arranged like the spokes of a wheel, and then, leaving 

 the radii, crowd above the centre (the rest of the cell being pig- 

 mentless) gradually dividing into 8 or 12 pear-shaped bodies, or 

 merozoites. These separate from each other and individually 

 attack a fresh red cell, and this attack brings another paroxysm 

 of fever seventy-two hours after the previous one. The grains 



