518 ZOOLOGY 



disease which would, however, give immunity just as fully as 

 the severer forms. He succeeded in inoculating against fowl 

 cholera, splenic fever of cattle, and finally against hydro- 

 phobia. In the institute which bears his name similar principles 

 have been extended to bubonic plague, lockjaw, and other 

 diseases. Here also was discovered the antitoxin for diphtheria. 

 Robert Koch, born in 1843, is the Pasteur of Germany. He 

 discovered and isolated the germ of tuberculosis (1881) and of 

 Asiatic cholera (1883). Sir Joseph Lister the great English 

 surgeon, born in 1827, using Pasteur's discoveries first applied 

 antiseptics to wounds in order to destroy the germs that might 

 enter. This was the foundation of aseptic surgery which under- 

 takes so to sterilize everything brought near an operation that 

 germs shall not enter at all. 



One of the most interesting things to hold in mind about 

 biological discoveries is this: it is impossible to tell how impor- 

 tant to human welfare any discovery may prove to be. No one 

 could have imagined that these students with the microscope 

 studying the organisms of decomposition would be led gradually 

 to the most profoundly important facts bearing on human life. 

 It was not quite 200 years from the discovery of bacteria until 

 Pasteur had discovered a way to overcome some of the diseases 

 produced by them. 



Other fields in which the discoveries of the students of 

 biology have been most valuable in practical life are : the breed- 

 ing and improvement of our food and forage plants; the im- 

 provements of the domestic animals; the encouragement of 

 wild food animals, as oysters and fish; the preservation of 

 foods; conservation of forests; the holding in check the pests, 

 largely insect, that often threaten to exterminate domestic 

 plants and animals. In these fields great progress will continue. 



With our increased knowledge of heredity and breeding, 

 scientists are asking the question whether these principles which 

 have done so much to improve the races of plants and animals 

 may not be used to secure more rapid progress in man. Pearson, 

 Bateson, Davenport and others claim perfectly soundly that 

 many imperfections, such as imbecility, epilepsy, criminality, 

 insanity, and other inheritable weaknesses, are bred back into 



