LAWS OF VARIATION '213 



the view that groups of species are descended from some 

 other species, and have been modified through natural 

 selection, I think we can obtain some light. First let 

 me make some preliminary remarks. If, in our domestic 

 animals, any part or the whole animal be neglected, and 

 no selection be applied, that part (for instance, the comb 

 in the Dorking fowl) or the whole breed will cease to 

 have a uniform character: and the breed may be said to 

 be degenerating. In rudimentary organs, and in those 

 which have been but little specialized for any particular 

 purpose, and perhaps in polymorphic groups, we see a 

 nearly parallel case; for in such cases, natural selection 

 either h.is not or cannot have come into full play, and 

 thus the organization is left in a fluctuating condition. 

 But what here more particularly concerns us is, taat 

 those points in our domestic animals, which at the pres- 

 ent time are undergoing rapid change by continued selec- 

 tion, are also eminently liable to variation. Look at the 

 individuals of the same breed of the pigeon, and see 

 what a prodigious amount of difference there is in the 

 beaks of tumblers, in the beaks and wattle of carriers, 

 in the carriage and tail of fantails, etc., these being the 

 points now mainly attended to by English fancierSo 

 Even in the same sub-breed, as in that of the short- 

 faced tumbler, it is notoriously difficult to breed nearly 



a| perfect birds, many departing widely from the standard. 



re-| There may truly be said to be a constant struggle going 

 on between, on the one hand, the tendency to reversion to 

 a less perfect state, as well as an innate tendency to new 

 variations, and, on the other hand, the power of steady 

 selection to keep the breed true. In the long run selec- 



lOlltion gains the day, and we do not expect to fail so com- 



