THE MALABIAL MOSQUITOES 



103 



The larv?p first studied — those which hatched from the 

 eg-gs on April 30th — grow very slowly for a number of 

 days. This was partly owing to cool weather in the early 

 part of May, and partly, I believe, to the absence of 

 proper food. They were reared in glass jars of water, with 

 sand at the bottom and a willow twig- rooting- in the sand. 



Fig. 21. — Full-grown Larva of Anopheles macvMpennis slinwins: head 

 upside down, with lop of head above, at left ; greatly enlarged. (Au- 

 thor's illustration.) 



As above noted, they swallowed every small particle float- 

 iug on the surface of the water, and the dark coloration 

 shown in Fig. 18 was largely due to the fact that most of 

 these food particles were dark colored. About the lOtli of 

 May, the larvae having passed through two molts, a small 

 quantity of the green algiie growing on the lily ponds on 

 the Department grounds was placed in the jar. The 



