THE MALARIA TOXIN 647 



however, are not met with at the very commencement of 

 the attack, but appear in a week or so, and may not 

 disappear until some weeks after the termination of the 

 attack. This parasite is met with in the sub -tertian, or 

 so-called malignant, types of fever, which are charac- 

 terised by irregularity of the fever, considerable blood 

 destruction, often accompanied by hsemoglobinuria, and 

 cachexia ; coma is another complication in certain 

 instances, probably caused by massing of the parasites in 

 the cerebral capillaries (Plate XXX, a). 



The cure of malaria by quinine is regarded as being due 

 to a poisonous action on the parasites analogous to that 

 exerted on numerous protozoa, amoebae, for example, 

 being injuriously affected by so little as a 1-50,000 solution 

 of quinine hydrochlorate. 



No toxin can usually be demonstrated in the blood of 

 those suffering from a malarial attack, but Rosenau and 

 his co-workers have found that the filtered blood, taken 

 when the temperature is rising, produces a malaria-like 

 paroxysm. 



Bass succeeded in obtaining multiplication of the 

 parasites in vitro by defibrinating infected blood, and 

 adding a little of the defibrinated blood to a mixture 

 of equal parts of human serum and 25 per cent, glucose 

 solution and incubating anaerobically at 37 C. 



About 12 per cent, of malaria cases not suffering from 

 syphilis are stated to give a positive Wassermann reaction, 

 but only during the acute stage. 



A malaria-like parasite (Plas. Kochii) occurs in apes, in which 

 it produces fever. 



The nature of Blackwater fever, so called from the presence of 

 hsematuria and hsemoglobinuria, has given rise to much discussion. 

 By some it is considered to be a disease sui generis, of unknown 

 etiology. By others it is regarded as a form of malaria, either of 

 an intense type, or in which the kidneys are especially involved, or 



