BIOLOGY IN HUMAN AFFAIRS 



are similarly engaged in the study of animals which furnish 

 milk, meat, eggs, silk, and honey. Current investigations 

 of especial importance deal with the diseases which affect 

 such economically valuable animals and with the heredi- 

 tary factors which determine the qualities of various breeds, 

 with the result that their productiveness is being contin- 

 ually increased. 



These examples, chosen from among many, will serve 

 to illustrate how zoology is contributing to human welfare 

 by increasing the real wealth that is available in the form 

 of useful things. Many agricultural products are made 

 abundant and cheap by improved methods of controlling 

 destructive pests; and the value per head of domesticated 

 animals is greatly increased by scientific breeding according 

 to the principles of modern genetics. All such results 

 depend ultimately upon purely zoological knowledge; and 

 many of them have issued directly from specially directed 

 research. Altogether, an enormous increase in wealth is 

 represented; and if this increase is not felt at once by the 

 ultimate consumer, it is the fault of our economic system, 

 not of science. 



IV 



Given a satisfactory degree of health and wealth, the 

 welfare of a human being — his chance for living the good 

 life — still depends very largely upon the social relations 

 in which he finds himself. And since man is primarily an 

 animal species, his social relations are bound to be formed, 

 in part, upon zoological principles. Perhaps the two most 

 important relations are concerned with union for defense 

 and with the family. These have a long zoological history; 

 and we may consider them briefly as appropriate examples 

 to illustrate our present point of view. 



The social mode of life is, in many respects, of great 

 advantage; chiefly, perhaps, because of the scope it affords 



[310] 



