BY JOHN SHIRLEY, B.SC. 73 



some types of malaria from the so called " Crescent Body," in 

 others from large extra-corpuscular plasmodia. They are only 

 seen after blood has been drawn and oxygenated. 



CRESCENT BODIES. 



These are shaped something like caraway seeds, are trans- 

 parent, with melanin bodies about their central zone, and are 

 partly clothed with the remains of the blood corpuscles in which 

 they developed. The crescents are usually uniform in appear- 

 ance, twin crescents rarely occur. Mannaberg's suggestion that 

 the crescents are formed bythe conjugation of two ordinary 

 Plasmodia is the most likely one. 



The crescent body is the parent of the flagellated body, 

 and the gradual change from one to the other may be readily 

 followed. The crescent becomes an oval, then a sphere, the 

 pigment bodies form a sphere within a sphere, then they begin 

 to dance about, finally the flagella shoot out from the periphery 

 and the flagellated body is complete. 



Ross has shown that when blood drawn from the human 

 subject is kept from the air no flagellated bodies are formed. 

 On the other hand exposure to the air, or the addition of water 

 to the slide favours flagellation. 



FUNCTION OF FLAGELLATED BODY. 



From the fact that the flagellated body does not enter into 

 existence until the blood has left the vessels, it is evident that 

 the function of the flagellum must lie outside the human body — 

 in fact, that the flagellated body constitutes the first phase of 

 the extra-corporeal life of the plasmodium. 



THE MOSQUITO. 



As the Plasmodium while in the circulation is always 

 enclosed in a blood corpuscle, and is therefore incapable of leaving 

 the body by its own efforts, it must be removed by some suctorial 

 insect common in the haunts of malaria. 



Surgeon-Major Ross has shown that the crescents ingested 

 by mosquitoes, fed on malarial blood, become transformed into 

 spheres, and then into flagellated bodies. It is now known that 

 these flagella detach themselves and coalesce with other non- 

 flagellated bodies, which then become endowed with locomotive 

 powers, and penetrate through the wall of the stomach of the 

 mosquito, embedding themselves among the muscular fibres 



