82 



THE AMERICAN NATURALIST [Vol. XL V 



once struck with the fact that one culture is formed of 

 individuals that are throughout and constantly larger 

 than those of another culture. 



And here, in view of that extraordinary cry "no here- 

 dity without a correlation table" 3 (a cry that at once 

 annihilates most Mendelian evidence of heredity), it may 

 be well to define a little more precisely what is meant by 

 saying that the diverse sizes are hereditary in the differ- 

 ent races. It means that if you keep your different geno- 

 types side by side under precisely the same conditions, 

 you will find whenever you choose to examine and meas- 

 ure them, that each has a characteristic size, differing 

 from that of the others. If therefore you follow the 

 diverse lines from generation to generation you will get 

 a set of chains, each with links differing characteristically 

 throughout from the links of the other chains. It means 

 that it is possible to predict the diverse relative sizes that 

 will be found in the different races, and that when you 

 examine them a hundred generations later, you will find 

 the prediction correct. These striking facts are what are 

 meant by the statement that the diverse sizes are heredi- 

 tary in the different lines— and the way to determine 

 whether the statement is true or not is to examine the 

 lines from generation to generation to see if the state- 

 ment is verified. To neglect this obvious fact ; to mix all 

 your lines together and then, in order to find out if size is 

 inherited, to laboriously work out coefficients of correla- 

 tion by refined biometrical methods — is like cutting serial 

 sections ten microns thick of an eel, in order to find out 

 whether it has an alimentary canal. Persons have been 

 known to so bedevil material with refined histological 

 methods as to quite miss the alimentary canal of an eel. 

 The way to see it is to open the animal up and take a look 

 at it. The way to see diverse genotypes is to isolate them 

 and look at them and measure them and compare them. 

 If the use of correlation tables should succeed in obscur- 

 ing these striking facts (as should not be the case with 

 proper handling) this would merely show the worthless- 



