MALARIA AND THE MALARIAL PARASITE. in 



understood, enter fresh blood corpuscles and appear there as pale specks 

 in the haemoglobin. These pale specks, if watched in perfectly fresh 

 blood, are seen to be possessed of very active amoeboid movement. 

 They throw out pseudopodia in various directions and wander about 

 through the haemoglobin of the corpuscle. After a time they increase 

 in size by assimilating the haemoglobin. By and by there appear 

 somewhere in the parasite those specks of black pigment which we saw 

 in the mature animal. Later they increase still further in size until 

 they come to occupy half, and finally nearly the whole, of the blood 

 corpuscle. Again there is concentration of pigment and the forma- 

 tion of little sporules. This is the cycle, as described by Golgi, of the 

 tertian and quartan parasite. The cycle of the tropical or aestivo- 

 autumnal parasite corresponds in plan almost exactly with that of the 

 quartan and ordinary tertian parasite. 



It was found that the life cycles of these parasites ran parallel with 

 the clinical cycle of malarial disease. It was found that when the 

 parasite had arrived at maturity the apyretic interval in an ague was 

 about to conclude, and that when the parasite had arrived at the 

 sporulating stage the patient had entered on the shivering stage of his 

 fever. During that and the succeeding hot and sweating stage the 

 spores had entered the red blood corpuscles, and when the parasite had 

 ensconced itself in the red blood corpuscle and begun to grow, the 

 fever had come to an end. It was found in tertian fever that the 

 cycle of the parasite took forty-eight hours to complete, exactly the 

 length of the cycle of the clinical phenomena. In quartan fever the 

 cycle took seventy-two hours, exactly the length of the clinical cycle of 

 that form of malarial disease. In the malignant or tropical fevers there 

 was found to be a similar correspondence between the cycle of the 

 parasite and the cycle of the disease. It was found that with each re- 

 curring paroxysm of fever there was a renewal of the life of the para- 

 site, and that in this way the life of the parasite was continued from 

 period to period and from cycle to cycle for weeks or even, especially in 

 the case of quartan malaria, for months. Now this explains very well 

 the way in which the malaria parasite contrives to maintain its existence 

 in the human body, but it does not explain how it passes from host to 

 host, neither does it explain certain appearances that Laveran and every- 

 body else who has studied the subject have witnessed. In malarial 

 blood you sometimes see that peculiar body, the flagellated body, 

 which I have already alluded to as consisting of a sphere surrounded 

 by from one to six or seven long tentacles or arms in a state of con- 

 tinual agitation. Neither does it explain the peculiar crescent-shaped 



body which also so pointedly arrested Laveran's attention 



. Golgi's scheme leaves the passage of the parasite from host to host and 

 also the nature of these two bodies unexplained. What relation have 



