SUBTERTIAN MALARIAL FEVER 41 



tendency, so marked in tertian and quartan, for the 

 parasites all to sporulate about the same time is less 

 constant. Subtertian parasites of all ages may be found 

 at the same time in blood removed from the viscera, 

 though a majority may be about the same age. The 

 pyrexial attack following sporulation is therefore neces- 

 sarily less defined, as the toxin is being liberated during a 

 far longer period. The cold stage is less often marked 

 by a rigor, frequently merely by a feeling of chilliness ; 

 the hot stage is prolonged and the sweating stage is often 

 intermittent, consisting of a series of attacks of dia- 



TIME 



r 



105 

 104 

 103 

 1-02 

 I Of 



too 



99 

 98 

 97 

 96 



zss 



FIG. 14. Subtertian Malaria with definite Tertian Periodicity. 



phoresiswith hot dry intervals ; the whole pyrexial period 

 may last for more than twenty-four hours. The interval 

 in such cases is short, as the whole cycle of development 

 of the parasite appears to be under forty-eight hours 

 (figs. 14 and 15). 



In other cases the pyrexial attack is still more pro- 

 longed, and the interval correspondingly shortened. Not 

 uncommonly in a severe attack there is no interval during 

 which the temperature is normal, but merely a remission. 

 Such a fever is therefore not intermittent, but remittent 

 (fig. 16). Vomiting is common and may be persistent. 

 When exceptionally severe and bilious, particularly if 



