178 SCIENCE REMAKING THE WORLD 



is within the reach of experimental study as to causes 

 and methods, and the results are leading to conclusions 

 that may vary with the investigator, but which will be 

 checked up by further investigation. The phylogenetic 

 advance of species, however, is still within the region of 

 inference. It is something like the difference between 

 the tracks in a switchyard and the main line. We 

 have succeeded in investigating the switching, but the 

 through trains are still baffling. 



PRACTICAL RESULTS 



The experimental study of evolution, leading to the 

 development of the science of genetics, resulting in in- 

 ^creasing knowledge of the laws of inheritance, has led to 

 practical results which the public in general do not ap- 

 preciate. I wish to refer to two of these by way of 

 illustration. 



i. THE REVOLUTION IN AGRICULTURE. It seems a 

 far cry from speculations concerning evolution to a 

 revolution in agriculture, but the continuity is un- 

 broken. Speculation led to observation; observation 

 led to experimentation; experimentation resulted in 

 discovering the laws of inheritance; and the application 

 of these laws has enabled us to handle plants and ani- 

 mals in a way that was never dreamed of before. It is 

 a good illustration of the fact that there is no sharp 

 dividing line between what is called pure science and 

 applied science, for pure science may prove to be enor- 

 mously practical. 



A brief statement will illustrate the agricultural re- 

 sults in the application of our knowledge of inheritance. 



