239 



disappearance of parasites we shall refer in the succeed- 

 ing section. 



1. On Young Parasites (malignant tertian). 

 When quinine is given at the time of their first appear- 

 ance in the circulation, the parasites continue in the 

 circulation for a variable period of time depending 

 upon the amount of quinine and probably on other 

 unknown factors. Although parasites are still found 

 yet their growth is arrested, and the outburst is not 

 followed by large forms, presegmenting, and eventually 

 fission forms. It must be noted that quinine may have 

 no such inhibitory effect at all. 



2. On Large Parasites. The parasites still go on 

 developing as far as presegmenting and segmenting 

 forms, but generally there is no subsequent production 

 of young forms. 



3. On Presegmenting and Segmenting Forms. 

 These are, as we have said, rarely found in the circu- 

 lation, but if quinine is given at the time that corres- 

 ponds to this stage, the subsequent effect is that very 

 few young rings appear at the next attack. 



QUININE HAEMOGLOBINURIA 



Between this phenomenon and blackwater fever 

 there is, in our opinion, practically no difference. It 

 is apparently true that cases of blackwater fever do 

 rarely occur in which no quinine has been previously 

 administered, and in which we have the exciting 

 cause of ' chill,' other drugs, ' exertion,' etc., but it 

 does not effect the position that quinine, not necessarily 

 in large doses, is the common cause of this phenomenon. 



It occurs only in those who have previously 

 suffered from malaria, and, in fact, there is considerable 

 evidence to shew that it occurs frequently in direct 

 association with a malarial infection. It has often been 



