14 



Insects and Disease 



logical effect produced may be due to the toxins or 

 poisonous matters that are given off by the parasite 

 while it is living in the host's body. Thus it is be- 

 lieved that the malarial patients usually suffer less 

 from the actual loss of red blood-corpuscles that 

 are destroyed by the parasite than they do from 

 the effects of the poisonous excretions that are 

 poured into the circulation when the thousands 

 of corpuscles break to release the parasites. 



One other point in regard to the relation of the 

 parasite to its host and this part of the subject may 

 be dismissed. From our standpoint we look upon 

 the presence of parasites in the body as an ab- 

 normal condition. From a biological standpoint 

 their presence there is perfectly normal; it is a 

 necessary part of their life. We think that they 

 have no business there, but from the viewpoint of 

 the parasites their whole business is to be just 

 there. If they are not, they perish. And when we 

 take a dose of quinine or other drug we are killing 

 or driving from their homes millions of these little 

 creatures who have taken up their abode with us 

 for the time being. But they interfere with our 

 health and comfort, so they must go. 



