ZOOLOGY AND HUMAN WELFARE 



The human race is a zoological species; it is one among 

 the almost one million kinds of animals that have been 

 scientifically studied; it is bound up with zoology as with 

 no other science. The objective study of animals and the 

 body of knowledge and doctrine derived from such study 

 must therefore have peculiar importance for mankind, 

 and we are here interested to see some of the ways in which 

 zoology bears upon the phases of existence which we have 

 distinguished as the necessary elements in human welfare. 

 Zoology contributes to human health because the principles 

 of hygiene and normal physiology are zoological and be- 

 cause many diseases are caused or carried by animals; to 

 wealth because many animals are economically useful 

 or injurious; to social relations because human reproduction 

 and heredity are fundamentally animal in nature; to intel- 

 lectual outlook because zoological theory forms an im- 

 portant part in our modern views of psychology, morals, 

 and progress. 



II 



The aim of hygiene is to maintain conditions favorable 

 to the normal activity of the human machine. Apart from 

 the fragmentary and often dubious lessons of ordinary 

 experience, this aim is accomplished by relying upon the 

 discoveries of physiology, a branch of zoology which has 

 made most of its important gains through studying the 

 functions of organs in animals. By using other mammals, 

 such as the dog, cat, and guinea pig, medical men can 

 extend very materially the field of experimentation, which 

 is strictly limited (though not entirely closed) when they 

 are dealing with human cases. And the zoological fact 

 that these animals are in many respects similar to the hu- 

 man species makes the results of such experimentation 

 immediately applicable, in many instances, to the study 

 of human physiology, normal or pathological. 



[293] 



