THE STUDY OF HEREDITY 331 



to hold that there is really any fundamental difference between 

 what are commonly called " natural " and " artificial " selection. 

 What we know as artificial selection is merely the experimental 

 proof of the effect of selection upon variations ; it does not 

 matter in the least whether the selection be applied by man or 

 by other factors in the environment of the organism. The only 

 difference is that the one is under the control, conscious or 

 unconscious, of an experimenter, whilst the other is not. But 

 he entirely missed the point I wish to emphasise here, and that 

 is, that domesticated races possess a character in common or 

 rather an exaggeration of a character which is not present in 

 wild races. This is a tendency to produce comparatively large 

 variations. Take even the most inbred stocks which are said 

 to breed quite true and to impress their peculiar characters 

 upon the offspring when crossed with another breed. Look at 

 the pedigrees. The same individuals appear constantly as 

 ancestors in the pedigrees of each descendant. This means 

 that only those individuals have been used for breeding 

 purposes who exhibited the desired variations ; what is more 

 important, that there were but few such individuals. Then, if 

 in such a pedigree we look at characters which were not the 

 objects of selection, as colour in racehorses, we find such 

 variations common as are rarely or never found in wild animals. 

 Domesticated races are, in fact, far more variable than are wild 

 races. Why ? Man is generally unable to detect small 

 differences. " He has always selected animals or plants which 

 vary from the mean of the race more than did their fellows. 

 Whatever else he has selected then, he has always selected 

 variability, which is just as much a character as anything else." ! 

 Those characters which in the domesticated races behave in the 

 Mendelian manner may therefore reasonably be regarded as 

 recent variations in individuals which have been rapidly 

 exaggerated in the offspring by the mode of selection. Man, 

 in his process of selection, has substituted his desires for many 

 other factors in the environment and has allowed characters in 

 which he was not interested to run riot in a manner that would 

 certainly have entailed the destruction of the organism if it had 

 not been protected by him. I would suggest that these 

 characters which are apparently recent and which are trans- 

 mitted alternatively should be called "individual" or "personal" 



1 Hereditary Characters, p. 71. 



