Chap. XX. UNCONSCIOUS SELECTION. 211 



methodical and unconscious selection. In both cases man pre- 

 serves the animals which are most useful or pleasing to him 

 and destroys or neglects the others. But no doubt a far more 

 rapid result follows from methodical than from unconscious 

 selection. The "roguing" of plants by gardeners, and the 

 destruction by law in Henry VIII.'s reign of all under-sized 

 mares, are instances of a process the reverse of selection in the 

 ordinary sense of the word, but leading to the same general 

 result. The influence of the destruction of individuals having 

 a particular character is well shown by the necessity of killing 

 every lamb with a trace of black about it, in order to keep the 

 flock white ; or again, by the effects on the average height of 

 the men of France of the destructive wars of Napoleon, by 

 which many tall men were killed, the short ones being left to 

 be the fathers of families. This at least is the conclusion of 

 those who have closely studied the subject of the conscription ; 

 and it is certain that since Napoleon's time the standard for 

 the army has been lowered two or three times. 



Unconscious selection so blends into methodical that it is 

 scarcely possible to separate them. When a fancier long ago 

 first happened to notice a pigeon with an unusually short beak, 

 or one with the tail-feathers unusually developed, although 

 he bred from these birds with the distinct intention of propa- 

 gating the variety, yet he could not have intended to make a 

 short-faced tumbler or a fantail, and was far from knowing that 

 he had made the first step towards this end. If he could have 

 seen the final result, he would have been struck with astonish- 

 ment, but, from what we know of the habits of fanciers, probably 

 not with admiration. Our English carriers, barbs, and short- 

 faced tumblers have been greatly modified in the same manner, 

 as we may infer both from the historical evidence given in 

 the chapters on the Pigeon, and from the comparison of birds 

 brought from distant countries. 



So it has been with dogs ; our present fox-hounds differ from 

 the old English hound ; our greyhounds have become lighter ; 

 the wolf-dog, which belonged to the greyhound class, has become 

 extinct; the Scotch deer-hound has been modified, and is now 

 rare. Our bulldogs differ from those which were formerly used 

 for baiting bulls. Our pointers and Newfoundlands do not 



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