2 39 
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 
