TRUE RELATION OF SCIENCE TO INDUSTRIES 293 



years, has, as thoroughly as time and opportunity have 

 permitted, investigated the phenomena of variability, 

 heredity, and selection, and as a result the practical 

 man has now at his disposal a vast array of facts, which, 

 a few years ago, were wholly unknown to him. 



IMPORTANCE OF VARIATION. 



Many of the causes of variation have been discovered. 

 Chief among these known causes are climate and condi- 

 tions of life. Thus meteorology again comes into play 

 as an important factor in practical agriculture. Oth- 

 ers are still unknown, but we do not despair of the dis- 

 covery of many of these. Heredity is a natural prin- 

 ciple so well known that we are astonished only when it 

 fails to act. But science has done much to sort out and 

 arrange the facts connected with its phenomena, al- 

 though its laws have not yet been formulated. Science 

 has shown that selection is a universal principle, and 

 that it is of two kinds, natural and conscious, though it 

 is not implied by this classification that conscious se- 

 lection is unnatural. A good general example of con- 

 scious selection is the well-known fact that breeders gen- 

 erally keep the finest animals for breeding purposes, 

 and thus keep their animals up to a high degree of per- 

 fection. In this way science, consciously or uncon- 

 sciously, continually improves the condition of ani- 

 mals. 



A few examples, illustrating the topic under consid- 

 eration, will serve better than any argument of my own 

 to show what science may thus accomplish. 



EXAMPLES OF VARIABILITY, SELECTION, AND 

 HEREDITY. 



In the horse, conditions of life and climate produce 

 the greatest variations. Mr. Charles Darwin, in his 



