522 POPULAR SCIENCE MONTHLY. 



HEKEDITY AND EVOLUTION. 



By WILLIAM BATESON, M.A., F.R.S., 



PRESIDENT OF THE ZOOLOGICAL SECTION OF THE BRITISH ASSOCIATION. 



|~N choosing a subject for this address I have availed myself of the 

 -*- kindly usage which permits a sectional president to divert the 

 attention of his hearers into those lines of inquiry which he himself is 

 accustomed to pursue. Nevertheless, in taking the facts of breeding 

 for my theme, I am sensible that this privilege is subjected to a certain 

 strain. 



Heredity — and variation too — are matters of which no naturalist 

 likes to admit himself entirely careless. Every one knows that, some- 

 where hidden among the phenomena denoted by these terms, there 

 must be principles which, in ways untraced, are ordering the destinies 

 of living things. Experiments in heredity have thus, as I am told, a 

 universal fascination. All are willing to offer an outward deference 

 to these studies. The limits of that homage, however, are soon reached, 

 and, though all profess interest, few are impelled to make even the 

 moderate mental effort needed to apprehend what has been already 

 done. It is understood that heredity is an important mystery, and 

 variation another mystery. The naturalist, the breeder, the horticul- 

 turist, the sociologist, man of science and man of practise alike, have 

 daily occasion to make and to act on assumptions as to heredity and 

 variation, but many seem well content that such phenomena should 

 remain forever mysterious. 



The position of these studies is unique. At once fashionable and 

 neglected, nominally the central common ground of botany and zool- 

 ogy, of morphology and physiology, belonging specially to neither, this 

 area is thinly tenanted. Now, since few have leisure for topics with 

 which they can not suppose themselves concerned, I am aware that, 

 when I ask you in your familiar habitations to listen to tales of a no 

 man's land, I must forego many of those supports by which a speaker 

 may maintain his hold on the intellectual sympathy of an audience. 



Those whose pursuits have led them far from their companions can 

 not be exempt from that differentiation which is the fate of isolated 

 groups. The stock of common knowledge and common ideas grows 

 smaller till the difficulty of intercommunication becomes extreme. Not 

 only has our point of view changed, but our materials are unfamiliar, 

 our methods of inquiry new, and even the results attained accord little 

 with the common expectations of the day. In the progress of sciences 



