222 ENTOMOLOGICAL NEWS. [May, 'l2 



to represent graphically the main features of this life-cycle, as 

 simply and accurately as possible. 



It has seemed worth while to include more of the details 

 and to represent the whole less diagrammatically than in the 

 work cited. The nomenclature adopted is that of Schaudinn. 



By means of the double-headed mosquito I have endeavored 

 to show how the infection takes place through the biting of 

 the human victim and how multiplication takes place asexually 

 in the blood of that victim and sexually in the body of the 

 mosquito which has bitten the malarial patient. 



At "A" the spindle-shaped sporozoite is injected into the 

 finger together with the salivary secretion of the mosquito. It 

 develops into the pale amoeboid schizont which enters the blood 

 corpuscle, and developing there at the expense of the haemo- 

 globin, it deposits the characteristic melanin granules which 

 are excretory in nature. 



These developing parasites are of two kinds. Many of them 

 having become crescent-shaped within the corpuscles may be 

 sucked up by the mosquito biting the malarial patient as at 

 "B." Others however are destined to increase their kind by 

 sporulation in the blood of man. In these individuals the nu- 

 cleus breaks up, the elements arranging themselves near the 

 wall. Partitions begin to grow in from the wall until the 

 nuclei are entirely separate from one another and finally the 

 individual spores or merozoites are set free in the blood plas- 

 ma by the disintegration of the corpuscle. Many of these are 

 of course attacked and destroyed by the white corpuscles, but 

 many enter healthy red corpuscles and repeat the entire 

 process or develop into the type which, if swallowed by the 

 mosquito) begin a new development in the stomach of the in- 

 sect at "C." 



The crescents are the gametes. They leave the corpuscles, 

 become spherical in form and develop into either micro- 

 gametoblasts (male) or macrogametes (female). In the latter 

 case a small round body (perhaps a "polar" body) is extruded 

 and finally thrown off so that at this stage the mature macro- 

 gamete is ready for fertilization. In the case of the micro- 



