50 jK^s^rrroh's 



The three dirt'erent kinds of iiiidaria, namely, that in 

 which the fever recurs every two days, known as tertian 

 malaria, that in which the fever recurs every three days, 

 known as quartan malaria, and the severe autumn fever, 

 known as jestivo-autumnal fever or tropical malaria — by 

 far the most danf;erous of the three — are l)y some writers 

 supposed to be caused by distinct species of parasites. 

 This view is not held by other Avriters. But at all events, 

 the period of development of the sporulating- stage of the 

 organism ditiers in length of time. As is very well 

 known, it frequently happens that the malarial fever or 

 chill will recur every day. That means, in tertian mala- 

 ria, that there has been a reinfection on one of the alter- 

 nate daj\s, the development of the anuebulas being con- 

 stant in i)oint of time, one set sporulating twenty-four 

 hours after the other set. It is just as this sporulation 

 occurs — just as the spores are liberated into the blood 

 serum — just as the malarial spasm is about to begin, that 

 the administration of quinine is most effective. It seems 

 to kill the spores when they are liberated, but aju^ears 

 to have very slight efi'ect upon the organism when it is 

 enclosed in the red blood corpuscle. 



This sporulating develoi)ment, each of the liberated 

 spores attacking and entering new red c(n'puscles, may 

 continue as above stated indetinitely. ]>ut not all of the 

 amoebulas undergo this d(!veloiunent. Some of them, so 

 long- as they remain in the human body, apparent!}^ die 

 and are digested by the leucocytes. 



When, however, these forms are taken from the human 

 body, even when a blood sample is simply placed under 



