224 ANIMAL PARASITES 



Three different parasites producing different clinical entities 

 are known. According to the time, frequency, and order of the 

 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: 



1 i i i i i. Simple quotidian fever. 

 o i o i o i. Simple tertian fever. 

 ooiooiooi. Simple quartan fever. 



2 i 2 i 2 i 2. Double tertian fever. (Two infections.) 

 23123123. Triple quartan fever. (Three infections.) 

 20120120. Double quartan fever. (Two infections.) 



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

 o represents the afebrile day. 



PLASMODIUM MALARIJE (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, leaving only a narrow 

 rim, which later on disappears. Six hours before the next paroxysm, 

 schizogony begins. The grains of melanin are arranged like the 

 spokes of a wheel, and then, leaving the radii, crowd about the cen- 

 ter (the rest of the cell being pigmentless) gradually dividing into 



