DISEASES CAUSED BY ONE-CELLED ANIMALS 129 



or, popularly, malarial germs, with man and the mosquito. 

 Not all kinds of mosquitoes — and over a hundred species of 

 mosquitoes live in the United States — ^carry malaria germs. 

 In only a few kinds, certain ones belonging to the spotted- 

 winged genus Anopheles, can the malarial germs live and 

 multiply. But it is difficult for the non-expert to tell one 

 kind of mosquito from another and as the malaria-spreading 

 kinds are scattered over the whole country, all mosquitoes 

 should be avoided or fought. How mosquitoes live is told 

 in Chapter VIII and how to fight them in Chapter XV. 



The way in which quinine cures malaria is by its power of 

 killing the germs when they are in our blood. But we do 

 not know that they are there until a great many have been 

 produced by their rapid method of multiplication, and then 

 it takes some time for the quinine to make headway against 

 them. We should be saved much suffering by preventing 

 their getting a lodgment into the body at all. 



As the germs are not created in the mosquito's body but 

 only get into it by the sucking up of blood by the insect from 

 some person already suffering from the disease, another way 

 of fighting malaria is to prevent mosquitoes from having 

 access to malarial patients, in other words to isolate and 

 quarantine from mosquitoes any person suffering from 

 malaria. 



While malaria in America is not looked on as a fatal 

 disease — although in fact about 10,000 persons die each 

 year from its effects — elsewhere in the world, as in the 

 Mediterranean countries and especially in India, it is a very 

 terrible disease indeed, carrying off hundreds of thousands, 

 even millions of victims every year. In some of these 

 countries, notably in Italy, mosquito fighting is done on a 

 large scale under governmental control and expense. 



The malarial fevers are the principal diseases which in 

 our own country are produced by one-celled animals living 

 in our bodies. But elsewhere in the world other even more 



