HEREDITY. 



By Prof. William Bateson, M. A., F. R. S. 



As the subject of the addresses which I am to deliver here and in 

 Sydney I take " Heredity." I shall attempt to give the essence of 

 the discoveries made by Mendelian or analytical methods of study, 

 and I shall ask you to contemplate the deductions which these 

 physiological facts suggest in application both to evolutionary theory 

 at large and to the special case of the natural history of human 

 society. 



Eecognition of the significance of heredity is modern. The term 

 itself in its scientific sense is no older than Herbert Spencer. Ani- 

 mals and plants are formed as pieces of living material split from 

 the body of the parent organisms. Their powers and faculties are 

 fixed in their phj^siological origin. They are the consequence of a 

 genetic process, and yet it is only lately that this genetic process 

 has become the subject of systematic research and experiment. The 

 curiosity of naturalists has, of course, always been attracted to such 

 problems; but that accurate knowledge of genetics is of paramount 

 importance in any attempt to understand the nature of living things 

 has only been realized quite lately even by naturalists, and with 

 casual exceptions the laity still know nothing of the matter. His- 

 torians debate the past of the human species, and statesmen order its 

 present or profess to guide its future as if the animal man, the unit 

 of their calculations, with his vast diversity of powers, were a homo- 

 geneous material, which can be multiplied like shot. 



The reason for this neglect lies in ignorance and misunderstanding 

 of the nature of variation; for not until the fact of congenital 

 diversity is grasped, with all that it imports, does knowledge of the 

 system of hereditary transmission stand out as a primary necessity in 

 the construction of any theory of evolution, or any scheme of human 

 polity. 



The first full perception of the significance of variation we owe 

 to Darwin. The present generation of evolutionists realizes perhaps 

 more fully than did the scientific world in the last century that the 



''- Two addresses delivered, August 14 and 20, 1914, at the Australia meeting of the Brit- 

 ish Association for the Advancement of Science. lieprintod by permission from author's 

 pamphlet copy, London, 1914. 



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