SELECTION B Y MAN. 27 



to read several of the many treatises devoted to this sub- 

 ject, and to inspect the animals. Breeders habitually 

 speak of an animal'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 individual, 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 mold he K 

 pleases,"" Lord Somerville, speakins^ of what breeders ^ 

 nave 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 picture by a con- 

 noisseur; 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 

 by the enormous prices given for animals with a good ped- 

 igree; and these have been exported to almost every 

 quarter of the world. The improvement is by no means 

 generally due to crossing different breeds; all the best 

 breeders are strongly opposed to this practice, except some- 

 times among closely allied sub-breeds. And when a cross 

 has been made, the closest selection is far more indispen- 

 sable even than in ordinary cases. If selection consisted 

 merely in separating some very distinct variety and breed- 

 ing from it, the principle would be so obvious as hardly to 

 be worth notice; but its importance consists in the great 

 effect produced by the accumulation in one direction, 

 during successive generations, of differences absolutely 

 inappreciable by an uneducated eye — differences which I 

 for one have vainly attempted to appreciate. Not one man 

 in a thousand has accuracy of eye and judgment sufficient 

 to become an eminent breeder. If gifted with these qual- 

 ities, and he studies his subject for years, and devotes his 



