SELECTION BY MAN. 25 



compare the many breeds of dogs, each good for man in dif- 

 ferent ways ; when we compare the game-cock, so pertina- 

 cious in battle, with other breeds so little quarrelsome, with 

 "everlasting layers" which never desire to sit, and with the 

 bantam so small and elegant ; when we compare the host of 

 agricultural, culinary, orchard, and flower-garden races of 

 plants, most useful to man at different seasons and for differ- 

 ent purposes, or so beautiful in his eyes, we must, I think, 

 look further than to mere variability. We cannot suppose 

 that all the breeds were suddenly produced as perfect and 

 as useful as we now see them ; indeed, in many cases, we 

 know that this has not been their history. The key is man's 

 power of accumulative selection : nature gives successive 

 variations ; man adds them up in certain directions useful 

 to him. In this sense he may be said to have made for him- 

 self useful breeds. 



The great power of this principle of selection is not hypo- 

 thetical. It is certain that several of our eminent breeders 

 have, even within a single lifetime, modified to a large ex- 

 tent their breeds of cattle and sheep. In order fully to 

 realize what they have done, it is almost necessary to read 

 several of the many treatises devoted to this subject, and to 

 inspect the animals. Breeders habitually speak of an ani- 

 mal's organization as something plastic, which they can 

 model almost as they please. If I had space I could quote 

 numerous passages to this effect from highly competent 

 authorities. Youatt, who was probably better acquainted 

 with the works of agriculturists than almost any other in- 

 dividual, and who was himself a very good judge of animals, 

 speaks of the principle of selection as " that which enables 

 the agriculturist, not only to modify the character of his 

 flock, but to change it altogether. It is the magician's 

 wand, by means of which he may summon into life whatever 

 form and mould he pleases." Lord Somerville, speaking of 

 what breeders have done for sheep, says : " It would seem 

 as if they had chalked out upon a wall a form perfect in 

 itself, and then had given it existence." In Saxony the 

 importance of the principle of selection in regard to merino 

 sheep is so fully recognized that men follow it as a trade : 

 the sheep are placed on a table and are studied, like a pic- 

 ture by a connoisseur : this is done three times at intervals 

 of months, and the sheep are each time marked and classed, 

 so that the very best may ultimately be selected for breeding. 



What English breeders have actually effected is proved 



