VARIATION AND HEREDITY 117 



them without analysis is very apt to lead to 

 biological fallacy. Many of the differences 

 may be wrapped up with sex, and these can 

 be readily sifted out from the slumped total. 

 Others may be wrapped UP with a^ and 

 these can also be analyzed out. Others are 

 due to soTnetliinff unusual in the "nurture." 

 in the wide sense; that is, they are the direct 

 results of peculiarities in surrounding influ- 

 ences and ^^peculiarities of habit, ijucli 

 rJiangefi in thfl hnrtirn of plnntn npd animals 

 fl.re eYt.rjrQin J not int.n'nsio. in origin; tlifty^axft 

 acquired, not inborn. They are technically 

 called "acquired rhp^^^s" or much more 

 clearly ' ' rhpdificatJQJ>e . " They may be de- 

 fined as structural changes in a part of the 

 body, directly in^ii^d K 



or by some change in surroundings 

 and fliirtnrq generally, which transcend the 

 limit of organic elasticity and thus persist 

 after the inducing conditions have ceased to 

 operate. No convincing evidence of their 

 transmission has as yet been forthcoming. 



Now the point is that when we subtract 

 from tt] e total pf Q^gp^^H ffjff^^'^g^Jl 

 that can be regarded a <^iric|i virtual modi- 

 fications, we have a very ini-.ftrpst.iTig remain- 

 t.kiig Hpfinp nff g.g inhnrn or 



germinal var^t 1 ' 01 !*- -They arfi int.rir),m'c. not 



extrinsic; inborn, not made. We cannot 



