196 



DISEASES DUE TO PROTOZOA 



apparatus, and some of its secretion is left under the skin 

 when the mosquito bites and sucks blood. It is probably the 

 secretion from this gland which causes the itching of the 



FIG. 66. Larva of Culex (a) hangs nearly at right angles to water surface; 

 those of Anopheles (6) are parallel to the surface. (From Kolle and Hetsch.) 



FIG. 67. Body of Culex (a) when resting is held parallel to wall in a 

 curved position, that of Anopheles (6) at an angle of about 45 degrees and 

 is straight; wings of Culex (c) are generally not spotted; those of Anopheles 

 (d) are spotted. (From Kolle and Hetsch.) 



ordinary mosquito bite. This reproduction in the mosquito 

 requires seven to ten days. When a person is bitten the 

 parasites, left under the skin, penetrate their cell of choice, 

 the red blood corpuscle. In the body of this cell they have 



