366 The Animal Kingdom 



P. malaria c is a comparatively mild form, but relapses can occur many 

 years after an exposure. 



From the earliest records of human history, it is evident that the 

 problem of malarial control has occupied an important role. Of course, 

 it was not known what the cause of malaria was, but people were well 



MATURE 

 TROPHOZOITE 



ASEXUAL CYCLE 

 Fig. 117. — Life history of Plasmodium sp., the causative organism of malaria. 



