VARIATIONS, DUE TO REVERSION. 55 



be a limit to them. But, strangely enough, the deteri- 

 oration of each species under nature, and the capacity 

 of each species to regain what it has lost, slip Darwin's 

 memory, in connection with the question of the cause 

 of variations ; and, therefore, there exists, for him, no 

 assignable limit to the improvement of animals and 

 plants. He treats of variations under domestication, 

 as if they were clear gain to the species, to which the 

 varying individuals belong, and proceeds to estimate 

 thereupon a ratio of increase of development : Where- 

 as, as he himself shows, variations are but the re-ac- 

 quisition of what had been lost. Again : Is it not 

 much more scientific, to ascribe variations to a known, 

 scientific factor, such as is Reversion, than to ascribe 

 them to an " innate tendency," or to " profound ignor- 

 ance" ? 



Again he remarks (p. 51, Vol. ii, Animals and Plants, 

 &c): 



" From what we see of the power and scope of re- 

 version, both in pure races, and when varieties or spe- 

 cies are crossed, we may infer that characters of almost 

 every kind are capable of reappearing, after having 

 been lost for a great length of time." 



He might also have remarked : " From what we see 

 of the power and scope of reversion, both in pure races, 

 and when varieties are crossed, we may infer that char- 

 acters of every kind," which appear under domestica- 

 tion, and positive variations of every kind, which may 

 appear under nature, are not due to any " innate ten- 

 dency ;" but that they may be referred to this well- 

 known scientific factor, Reversion. 



