212 



DISEASES DUE TO PROTOZOA 



skin, penetrate their cell of choice, the red blood cor- 

 puscle. In the body of this cell they have the power 

 of undergoing an asexual division (see Fig. 63). The 

 minute form swells into a large body and breaks up 

 into small spores. When this mass of young forms 

 has reached a size too great for the red cell the latter 



FIG. 67 



In Culex the palpse (a) of the female are very short, of the male are longer 

 than the proboscis; in Anopheles the palpse (ft) of both sexes are about equal 

 in length with the proboscis. (From Kolle and Hetsch.) 



bursts, synchronously with which we have the chill. 

 By this bursting young forms are again set free in the 

 blood, capable of entering other red blood cells. Of 

 course, not all the cells are affected, but in severe cases 

 one of every thirty red blood cells may contain the 

 parasites. As a result of this, severe grades of anemia 

 result. The cycle of development from the young form 



