102 AN INTRODUCTION TO SCIENCE 



.direct effect t of\ environment, since acquired characters are 



But Wallace, Weissmann and most post-Darwinians 

 ' accept, thjs theorem. Some take the a priori 



' ground that trie transmission of acquired characters is 

 incomprehensible. Reproduction means, as they point out, 

 that the parent divides into two parts, one so large as to be 

 practically unaffected by the division ; the other a minute 

 cell, the ovule in a carpel, the pollen grain in an anther or 

 the corresponding cells in the two sexes of animals. Is it 

 conceivable, they ask, that the whole of the male parent, 

 with his acquired peculiarities, is mirrored in his " gamete," 

 and the whole of the female in hers? Other biologists 

 decline to accept the doctrine of the transmission of 

 acquired characters, on the ground that such transmission 

 has never been proved under any conditions we are able to 

 arrange, or within any period of time over which observa- 

 tions extend. We have, for example, instances of the 

 mutilation of thousands of successive generations without 

 any tendency towards the diminution of the organ removed. 

 Every cur's puppy flourishes a tail does its best to rise to 

 the dignity of a dog centuries after the passing of a law 

 that all except the dogs of the nobility who enjoyed sport- 

 ing rights, should be curtailed {court taille}. But for 

 reasons into which we cannot enter the evidence from 

 mutilation is by some biologists (by Darwin himself) ruled 

 out of court. 



The adaptation of the individual to his environment is a 

 matter of experience. A blacksmith's biceps are bigger 

 than those of a clerk. A seed sown in a new soil and under 

 a new climate produces a plant different in many respects 

 from its parent. But are these peculiarities transmitted to 

 offspring? If it could be shown that the seeds of the trans- 

 ported plant, when sown in the original habitat of the 

 species, produce plants which are unlike their wild neigh- 

 bours (in respects which cannot be accounted for by sup- 



