AGENTS OF DISEASE 279 



and wings are dry and firm, when it flies away. 

 The sexes are easily distinguished in the adult 

 mosquito, as the antennae of the male are hand- 

 some plume-like organs, and the palps are long 

 and hairy, giving the whole head a conspicuous 

 appearance. The antennae of the female have 

 very short hairs, and are inconspicuous, while the 

 complex mouth with its formidable lancets and 

 sucking proboscis is more highly developed than 

 in the male. While the male mosquito is 

 absolutely a vegetarian, only using its proboscis 

 to suck up vegetable juices, the female is a most 

 bloodthirsty creature, piercing the skin with her 

 stylets, and sucking up the blood until gorged 

 to repletion. It is the female mosquito that is 

 the transmitting agent of malaria from man to 

 man, for after the sexual generation of the 

 malarial parasite (drawn in with the blood she 

 has sucked from an infected person) has been 

 passed in her body, the resulting needle-shaped 

 spores accumulate in her salivary glands and 

 pass out through her mouth into the wound she 

 inflicts when stabbing a fresh victim. 



There is a stage or period in the life-history 

 of most creatures when they are more readily 

 destroyed than at any prior or subsequent 

 period, and it is this most vulnerable period that 

 has to be discovered and taken advantage of, in 

 fighting our insect foes. Now, in the case of the 

 mosquitos, it is during the aquatic larval and 

 pupal stages of their existence that they are 

 most easily destroyed, for they are confined 

 within the limit of the marshy, stagnant pools, 

 or water troughs, and they have to rise to the 



