VARIATIONS, DUE TO REVERSION. 83 



been suffered to run wild ; or little care has been taken 

 of it. Its offspring are placed under cultivation, and 

 they return to the condition in which their progenitor 

 was ; they have their legs, tusks, bristles, snout, &c, 

 reduced. This is negative reversion, however. This 

 is the dexterous way in which Darwin clouds the sub- 

 ject of the cause of the positive variations, which, as 

 he essays to prove, were successively accumulated, 

 and made to produce all positive developments. . This 

 is the manner in which he redeems his promise of 

 showing that his " two main divisions " of " unknown 

 causes," and of a known cause, graduate into each 

 other. 



All of the positive variations; all the positive changes; 

 all the positive improvements; all the positive incre- 

 ments of growth or of development; all the advances 

 made by organisms from comparative simplicity to 

 complexity of structure, which Darwin fain would 

 accumulate, ad infinitum; are due to Reversion. If 

 the conditions of the growth of a character, are taken 

 away, the character becomes reduced, or suppressed. 

 If Darwin desires to exalt adverse conditions, to the 

 dignity of " unknown causes," and show that species 

 may change one into another, by removes from com- 

 plexity to simplicity of structure, he stultifies his 

 theory of evolution, which predicates advance in de- 

 velopment; but, we are prepared to meet even that 

 issue, and do so meet it; for we show, in the chapters 

 following, treating of crossing and of close interbreed- 

 ing, that no individual is capable of any remove from 

 complexity to simplicity of structure, and that no 



