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Show 30 SELECTION BY :MAN. CII.AP.I. . h . them adaptation, not indeed to the IS t at we see In , f . 1' 1 nt's own good but to man s use or ancy. aruma s or. Pt' a seful to ' him have probab ly an·s en Some vana. 1ons u . . dd 1 b One step. many botanists, for Instance, su en y, or Y ' . . k h' h .b e1 1. eve tha t the fuller's teazle, with. Its boo . s, w IC. canno t b e n.v al led by any mechanical con. tnvance, Is on 1y a varw. t y of the wild Dipsacus ·' and th1s. amount o.f h may have suddenly arisen in a seedhng. So It c ange " . d h' · has probably been with the turnspit dog; an t Is Is known to have been the case with the ancon sheep. But when we compare the dray-horse and race-horse, the dromedary and camel, the various b~eeds of shee~ fitted either for cultivated land or mountain pasture, w1th the wool of one breed good for one purpose, and that of another breed for another purpose; when we c~mpare the many breeds of dogs, each good for man In very different ways; when we compare the g~me-cock, so pertinacious in battle, with other breeds so httle qu~rrelsome, with "everlasting layers" which never desire to sit and with the bantam so small and elegant; when w~ compare the host of agricultural, culinary, orchard, and flower-garden races of plants~ most useful to man at different seasons and for different 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 several 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 use:ul to him. In this sense he may be said to make for himself useful breeds. The great power of this principle of selection i~ not hypothetical. It is certain that several of our eminent breeders have, even within a single lifetime, modified to CHAP. I. SELECTION BY MAN. 31 a large extent some breeds of cattle and sheep. In order fully to realise 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 animal's organisation as something quite plastic, which they can model almost as they pleas~. If I had sp~ce 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 hi~s~lf a very good judge of an animal, ~peaks of the prinmple of selection as " that which enables the agriculturist, not only to modify the character of his .Jock, but to change it. altogether. It is the magician's wand, by means of whwh he may summon into life whatever form and mould he pleases." Lord Somerville ~peaking of what breeders have done for sheep, says:-' It would see~ a~ if they had chalked out upon a wall a form perfect. m Itself, and then had given it existence." That ~ost skilful breeder, Sir John Sebright, used to say, ~Ith respect. to pigeons, that "he would produce a~y given feather In three years, but it would take him SIX years to obtai~ h~ad and beak." In Saxony the importanc. e of the pnnmple of selection in regard to merino sheep IS so fully recognised, that men follow it as a t~ade : ~he sheep are pla~ed on a table and are studied, lik~ a picture 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. "Vhat English breeders have actually effected is proved by the enormous prices given for animals with a good pedigree ; and these have now been exported to ~lmost every quarter of the world. The improvement is Y no means generally due to crossing different breeds |