20 MICROBES AND THE MICROBE-KILLER, 



pear stock, such as the Le Conte, Chinese Sand-Pear, 

 Kiefer-Hybrid, and other fast-growing varieties, proved 

 successful by greatly improving the health and growth. 

 The health of very delicate tea roses is greatly improved 

 by budding them on strong growing, hardy varieties, 

 and many varieties of foreign grapes which failed to 

 grow in this climate are now successfully grafted and 

 raised on strong growing, hardy natural stock. Hybridi- 

 zation, cultivation, and selecting the best varieties of 

 plants and animals for propagation, tend to improve 

 them. Why should not the same course improve man ? 



If the same precautions were taken in perpetuating 

 the human family as are taken in breeding the lower 

 animals, we should not only attain to physical and men- 

 tal superiority, but we should in all likelihood obliterate 

 the causes of very much disease. 



Now, the system which we find to produce such dete- 

 riorating consequences in horses is exactly that which 

 we are carrying out every day and from year's end to 

 year's end in the propagation of mankind. In the hu- 

 man family we cannot follow the methods under which 

 the English racehorse of the present day has been de- 

 veloped, but we might find it not so difiicult to guard 

 against the propagation of disease. Let every man 

 marry none but a healthy woman, and let every woman 

 be careful to select none but a healthy husband, and 

 much disease, deformity of mind as well as body, and 

 general debility would be avoided and in course of time 

 killed out. No hereditary disease owing its existence 

 to micro-organisms could possibly be continued. But 

 where one or both parents have the germs of disease, 

 the offspring is not only liable but is almost certain 

 to be sickly and unhealthy, and the doctor will be 

 called simply to watch their downward progress toward 

 dissolution — victims of disease germs and of a process of 

 fermentation. 



