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Show 242 SELECTION. C HAP. XXI. remark· for we can m. no other way nn d· e rs tan·d the surprils'ti'n g amount ' of difference between van· eti· es 1·~ tll e parts or. .q u.a· 1. 1cs whi.C h are va1 u e d, wh I'l s t ot her parts retam nearly theu ougmal < - character. · 1. t The 1.e 0regom• g d1' scuss.w n n aturally leads to the questiOn, wua l . • • • is the limit to the possible amount of var~at~on m hany P 1 art . d tly is there any hnut to w at so ec-or quahty, an ' consequen ' . d fl . tl tw• n can e.uePe ct ? W'Il l a I·<a ce-horse ever be reme• ee•t er l• an Ech. pse.? Ca n our pri.z e-cattle and s.h eep be. stihll furhth er Im. -_ roved? vVill a gooseberry ever weJgh more t an . t at. piO P b L d , . 1852 ? vVill the beet-root m France duced y " on on m · · · f yi.e l d a grea t er percen t ag e of sugar? Will future vanetles ot wheat and other grain produce heavier CI:ops than our pr~sen van.e t "1 es ? These questions cannot be po. sitiv.e ly answer· ed'b but it is certain that we ought to be cauti~U~ m answermg y a t . In some lines of variation the hmit has probably been nega Ive. · f b · reached. y ouatt believes that the reductiOn o . one ~ln somet of our sh eep h as a1 r ea dy been carried so far that It .e ntal s grea delicacy of constitution.61 But seeing the great Impro:eme~t within recent times in our cattle and sheep, and espeCially m our pigs . seeina the wonderful increase in weight in our poultry of all ki~1ds uu~ina the last few years; he would be a bold ~an who would assert' that perfection has been reached. Echpse per h aps may never be beaten until all our race-horses1 have been rendered swifter, through the selection o~ the best 1o~·scs dming many generations; and then the old Eclipse may posstbly be eclipsed; but, as Mr. Wallace has remar~ed, there must be a~ ultimate limit to the fleetness of every ammal, whether under nature or domestication; and with the l10rse this limit h~s perhaps been reached. Until our fields are better manured, It may be impossible for a new variety of wheat to yield a heavier crop. ~ut in many cases those who are best qualified to judge do ~ot behove that the extreme point has as yet been reached even with respect · to characters which have already been carried to a high_standard of perfection. For instance, the short-faced tumbler-pigeon has been greatly modified; nevertheless, accordi~g to 1\'~r. ~aton,62 "the field is still as open for fresh competitors as It '' ~s one hundred years ago." Over and over again it lu.ts been saJd t~mt 61 Youatt 011 Sheep, p. 521. 6~ • A Treatise on the Almonu 'fumbler,' P· I. CHAP. XXI. SELECTION. 243 perfection had been attained with our flowers, but a higher standard has soon been reached. Hardly any fruit has been more improved than the strawberry, yet a great authority remarks,63 "it must not be concealed that we are far from the extreme limits at which we may arrive." Time is an important element in the formation of our domestic races, as it permitts innumerable individuals to be born, and these when exposed to diversified conditions are rendered variable. Methodical selection has been occasionally practised from an ancient period to the present day, even by semi-civilised people, and during former times will have produced some effect. Unconscious selection will have been still more effective ; for during a lengthened period the more valuable individual animals will occasionally have been saved, and the less valuable neglected. · In the course, also, of time, different varieties, especially in the less civilised countries, will have been more or less modified through natural selection. It is generally believed, though on this head we have little or no evidence, that new characters in time become fixed ; and after having long remained fixed it seems possible that under new conditions they might again be rendered variable. How great the lapse of time has been since man first domesticated animals and cultivated plants, we begin dimly to see. When the lake-buildings of Switzerland were inhabited during the N eolithio period, several animals were already domesticated and various plants cultivated. If we may judge from what we now see of the habits of savages, it is probable that the men of the earlier Stone period-when many great quadrupeds were living which are now extinct, and when the face of the country was widely different from what it now is-possessed at least some few domesticated animals, although their remains have not as yet been discovered. If the science of language can be trusted, the art of ploughing and sowing the land was followed, and the chief animals had been already domesticated, at an epoch so immensely remote, that the Sanskrit, Greek, Latin, Gothic, Celtic, and Solavonic languages had not as yet diverged from their common parent-tongue. 64 63 M. J. de Jonghc, in' Gard. Chron.,' 1858, p. 173. 64 Max. MUller, 'Science of Language,' 1861, p. 223. R 2 |
