6 NATIONAL TRENDS IN BIOLOGY 



In the fields of chemistry and physics, for example, 

 using two nonbiological sciences, one is very definitely 

 limited to certain specific substances and to the laws of 

 force, light, heat, and electricity. In biology, dealing as 

 it does with everything that is living or pertains to life, 

 there is practically no limit to one's field of endeavor. 

 Whether we think of the great North American chewing- 

 gum industry or the price of cotton and coffee, everything 

 which comes to mind in connection with such topics is 

 in some way involved in the subject of biology, for life 

 means everything that grows and moves, and develops 

 from the inside outward. Life includes all the plant and 

 animal world. Within its boundaries, the range of investi- 

 gation may run from a study of the diseases of plant 

 crops and the parasitic enemies and diseases of your herds 

 of cattle, to the length of life allotted to yourself and 

 family. Every step is determined by a biological law ; and 

 to learn that law and apply it, is the great fundamental 

 object of every biological worker, from those who spe- 

 cialize in entomology and plant pathology to human 

 medicine. 



What a tremendous difference the efforts of such work- 

 ers have made upon the entire world may be judged by 

 a few examples. As several writers have pointed out, the 

 downfall of the classic civilization of bygone days was 

 undoubtedly due to the malarial mosquito. Epidemics 

 of the past, breaking out in times of war, have completely 

 changed history. 



Many archaeologists hold that yellow fever was the 



