HORSES, SHEEP, AND MAN 367 



It would be interesting to have precise information as to the 

 progeny of Eurasians who intermarry, for here the original 

 hybrids result from the mixture of two very distinct races. 



Mr. Bateson cites (from Nettleship) a case of congenital 

 cataract which continued to reappear through several genera- 

 tions. He calls the congenital cataract a dominant character, 

 though it was not exhibited in all the F^ generation ; the normals 

 had only normal offspring ; the affected members had children 

 of both kinds in approximately equal numbers, viz. 29 (? — i) 

 and 26 (+ ?). The pedigree is given elsewhere. Of this and of 

 another pedigree, Bateson says that they " are in good agree- 

 ment with the Mendelian scheme," but they do not seem to us 

 at all convincing, unless the exception proves the rule. 



If Mendelian phenomena occurred in man, it seems unlikely 

 that they should have escaped detection, since crossings of races 

 have been very common. The intermarriage of mulattos should 

 surely have yielded some clear results. There is of course the 

 difficulty that the inbreeding necessary to bring out Mendelian 

 segregation is not sufficiently close in mankind. 



It appears to us that something might be made of the fact 

 that there is very frequent marriage, e.g. in Britain, between 

 the dark and the fair. This has gone on for centuries, and yet 

 the two types are always with us, and are often strikingly seen 

 in one household. The monotony of an average blended brown 

 has certainly not become general. But this is a complex 

 and difficult inquiry. 



§ 5, Mendel's Discovery in Relation to Other Conclusions 

 Conception of the Organism. — A keen critic has pointed out 

 that the Darwinian or Selectionist theory of evolution is obviously 

 a projection on nature of anthropomorphic ideas partly due to the 

 keen competition of the industrial age, partly due to a temporary 

 pressure of over- population, partly due to the process by which 

 mechanical devices, such as spinning and weaving machinery 



