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Show 34 SEi..ECTION BY :MAN. [CHAP. I. the o-ame-cock iO pertinacious in battle, with oth~~· brf~~s so little q uar;elsorne, with " everlasting layers 1f nc ~ never desire to sit, and with the bantam .so SJna an. ele ant . when we compare the host of agncultural, cuhnai~, or~hard, 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, ~e know that this has not be~n their history. Th~ key IS ma:t'b power of accumulative selection : natu~e g~ves .successive variations ; man adds them up in certain directions "?-seful to him. In this sense he may be said to make for lnmself useful breeds. · . . The great power of this principle of select1on I~ not hypothetical. It is cert~in th~t sev~ral. of our ~1n1nent breeders have even within a smgle lifetime, Inodrfied to a large extent' some breeds of cattle and sheep. In order fully to realise what they have do_ne, it is almost ne~essary to read several of the many treatises devoted to th1.s subject, and to inspect the an~ma~s. Breeders ~abitua~ly speak of an animal's organisation as something quite las tic which they can 1nodel almost as they ple~se. If thad space I could quote numerous passages to this effect fro1n highly compete~t aut~orities. Y ouatt, w~o wa~ probably better acquainted :VIt? .the works of agncul~urists than almost any other Individual, and who was hl:nself a very good judge of an animal, speaks of th.e pnnci. ple of selection' as "that which enables ~he agnculturist, not only to modify the ?haracter of. ~1s ~ock, but to change it altogether. It 1s th~ magiCians wand, ?Y 1neans of which he may summon 1nto hf~ whateve~· 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. upoll: a w~ll a fo;,m perfect in itself and then had given It eXIstence. · T~at most skilful breeder, Sir John So bright, used to say, :VIth respect to pigeons, that" he would pro~uce .any g:ven feather in three years, but it would take h1m SIX yea1s to CHAP. I.] SELECTION BY MAN. 35 obtain head and beak." In Saxony the importance of the principle of selection in regard to merino sheep is so fully recognised, that men follow it as a trade : the sheep are placed on a table and are studied, like 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. What 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 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 som.etimes amongst closely allied sub-breeds. And when a cross has been made, the closest selection is far more indispensable even than in ordinary cases. If selection consisted merely in separating some very distinct variety, and breeding 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 qualities, and he studies his subject for years, and devotes his lifetime to it with indomitaqle perseverance, he will succeed, and may make great improvements; if he wants any of these qualities, he will assuredly fail. Few would readily believe in the natural capacity and years of practice requisite to become even a skilful pigeon-fancier. . The · same principles are followed by horticulturists ; but the variations are here often more abrupt. No one supposes that our choicest productions have been produced by a single variation from the aboriginal stock. We have proofs that this is not so in some cases, in which exact records have been kept ; thus, to give a very trifling instance, the steadily increasing size of the common goose- |