326 SCIENCE PROGRESS 



they originated in the remote past from characters that were 

 Mendelian is beside the question ; they certainly are not so now. 

 In following the behaviour of what are really small, more or less 

 individual differences, the Mendelian school have apparently so 

 lost sight of the bulk of the characters in the organisms they 

 have studied, that these comparatively slight differences are 

 treated by them as though they were the only characters that 

 exist. A very little consideration will show what a mistake this 

 is. Take the whole of the characters of man. I will not trouble 

 to deal even briefly with those which he possesses in common 

 with other animals lower in the scale than mammals, though 

 they are numerous enough to fill volumes. Among the characters 

 possessed by man in common with all other mammals but not 

 by other vertebrates are the special modification which provides 

 for the feeding of the young after birth ; hairs upon the skin ; 

 sweat and sebaceous glands ; a peculiar formation of the skull, 

 skeleton generally, and brain ; a particular form of red blood 

 corpuscle ; and the separation of the body cavity into two large 

 compartments by the diaphragm which provides an addition to 

 the breathing mechanism not found in other animals. I must 

 pass on to the nearest relations of man, the existing higher apes. 

 When we consider the characters common to man and the 

 chimpanzee or gorilla, we find that the resemblances extend to 

 the bulk of even minute details. Compared with the points of 

 resemblance the points of difference are small and very few. 

 The differences between the different races of men are smaller 

 and fewer. To me, therefore, it appears perfectly clear that the 

 overwhelming bulk of the characters inherited by each individual 

 is derived from very remote and prehuman ancestors. The 

 differences which constitute the characters studied by the 

 Mendelians are almost as nothing when considered in relation to 

 the characters which are common to all the members of the race. 

 But these characters common to all individuals obviously cannot 

 be transmitted alternatively. They are always present. It is 

 therefore evident that the characters that are inherited in the 

 Mendelian manner are really slight additions to or subtractions 

 from characters already present. If we choose even the largest 

 of such differences, albinism for instance, it is clear that this is 

 comparatively a small difference. Pigment is not entirely absent 

 from the organism, it is absent only from certain parts and in 

 most cases is not quite absent even from them. 



