PRESENT-DAY BIOLOGICAL THOUGHT 49 



the final analysis, rest upon the findings of biology and 

 biologists. 



On the positive side we find, from our survey of biolog- 

 ical opinion, that the most outstanding and important 

 findings of biology which have influenced mankind are 

 summarized under the following headings : 



1. Medicine and general health, especially through the 

 study of parasitology and disease prevention. In this con- 

 nection, one must not forget the remarkable results ob- 

 tained in the practical fields of medicine from such studies 

 as those made on malaria, yellow fever, typhoid fever, and 

 diphtheria, to mention only a few. 



2. Bacteriological and parasitological findings applied 

 to commercial processes, and insects and plant control, 

 which, in turn, affects the entire food supply of man. 



Closely connected with this latter work is that of ap- 

 plied genetics. Here questions like the following find 

 their answers: 



"How can we breed those types of plants and animals 

 which will thrive best, and present those characteristics 

 we desire in our own particular region of the world ?" 



"How can we make disease-resistant plants and 

 animals?" 



"How can we make the waste places of the earth 

 become of value to man?" 



"How increase the yield of crops?" 



"How can biology be brought to advance the work of 

 the agriculturist, the cattle breeder, etc.?" 



