THE SCIENTIFIC EVIDENCES OF 



laws of heredity, it follows that the individuals 

 composing each successive generation have a 

 general tendency to be better suited to their 

 surroundings than were their forefathers. And 

 this follows, not merely because in every genera- 

 tion it is only the flower of the race that is 

 allowed to breed, but also because if in any 

 generation some new and beneficial qualities 

 happen to appear as slight variations from the 

 ancestral type, these will be seized upon by 

 natural selection and added, by transmission in 

 subsequent generations, to the previously existing 

 type. Thus the best idea of the whole process 

 will be gained by comparing it with the closely 

 analogous process whereby gardeners and cattle- 

 breeders create their wonderful productions; for 

 just as these men, by always selecting their 

 best individuals to breed from, slowly but 

 continuously improve their stock, so Nature, 

 by a similar process of selection, slowly but 



