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Show 96 DARWINISM CHAP. been long dome. tica,ted in the Ea.st, the gold and silver carps; n.nd the:e present gre~Lt varia,tion, not only of colour but in the form and structure of the fins and other external oro·ans. In like manner, the only dome ticated insects, hive bees and silkworm moth , present numbers of remarkable varieties which h<tve been produced by the selection of chance variations just as in the case of plants and the higher animals. Cinumstances favourable to Selection by Man. It may be supposed, that the systematic selection which has been employed for the purpose of improving the races of animals or plants useful to man is of comparatively recenL origin, though some of the diff'erent races arc known to have heen in exi. tence in very early times. But Mr. Darwin has pointed out, that unconscious selection must ha,ve beo·tm to produce n.n eCfect as soon as plants were cultivated or anim;tls dome ticated by man. It would have been very soon ohserved that animals and plants produced their like, that seed of early wheat produced early wheat, that the offspring of very swi fL doo·s were also swift, and as every one wonld try to have a good mther than a bad sort this would necessarily lead to the low but ste<.Ldy improvement of aJl U. efnl plants and anim al ~-; subject to man's care. Soon there would ari. e distinct hrec<l s, owing to the varying uses to which the animal and plan ts were pnt. Dogs would be wanted chiefly to hunt one kin <l of. game in one part of the country and another kind elsewhere; for one purpose scent would be more importan t, for another swiftness, for another strength and courage, for ycL another watchfulness and intelligence, and this would sooJL lead to the formation of very distinct rn.ces. In the case of vegetables and fruits, different varieties would he found to succeed best in certain soils and climates; some migh t lw preferred on account of the quantity of food they prodnc<'<l, others for their sweetness and tenderness, while other. might be more useful on account of their ripening at a particnLtr season, and thus again distinct varieties wonld be est:Lblislwd. An instance of unconscious selection leading to di. tin ct results in modern times is afforded by two flocks of Leicester she<'p which both originated from the same stock, a.nd w r th en l)]'('d pure for upwards of fifty years by two gentlemen, Mr. Buckley IV VAlUATION UNDER D011 ESTICATION 97 nd Mr. Bt1rgess. Mr. Youatt, one of the greatest authorities on hreetlinu· domcsLic animals, says : "There is not a su picion cxi. tin•T in° the mind of any one at all acquainted with the subject tha.t the owner of either 9f them has devia~cd ir.t ~ny one in ·t<mce from the pure blood of Mr. Bakewell s or1g111al flock, and yet the difl'ercnce between the sheep pos essed hy t he. c two genLlemen is so great th:tt they have the appearance of beino· quite diff'erent varietie .. " In this case there was no desire t~ deviate from the original hrced, and the difference must have ~1,risen from some slight difference of taste or judgment in selecting, each year, the parents for the next y~ar's stock, combined perhaps with some direct efl'ect of the shght difference. of clinmte and soil on the two farms. Mo t of our domesticated animals all(l cultivated plants have come to us from the e<Lrl ie. t . cats of civili ation in Western A i<l, or Egypt, and ha.ve therefore been the subjects of human c;u·c and selection for . ome thousands of years, the result being that, in many cases, we do not know the wild stock from which they origirmlly sprang. The hor. e, the camel, and the common bull and cow :1,re nowhere fonnd in a wild state, and they h;.wo all be n do~ 'Sticate~l fr~m r?mo~e antiquity. The original of the domestiC fowl 1.s st1ll .wd<l 1.n Indi<l, and the Malay Island., and it was domestiCated 111 Indm and China before 1400 n.u. It was introduced into Europe about 600 B. •. Several distinct breeds were known to the Romans about the commencement of the Christian om, and they h:we since spread all over th_c civ!lised world and ~een subjected to a vast amount of .conscwus and ~~conscwus selection, to many varieties of chmate and .to d.IfJcrcnces of food· the result bein()' seen in the wonderful d1vers1ty of breeds which differ quite as 0 rcmarkably as do the different races of pigeons already described. In the ve()'etable kingdom, most of the cereals-wheat, barley, etc.-~re unknown as truly wild plants ; and the same is the case with many vegetables, for De Candolle states that out of 157 useful cultivated plants thirty-two are quite unknown in a wild state, and that forty more arc of doubt~nl origin. It is not improbable that most of these do exist wild, but they have been so profoundly changed ~y thousands of years of cultivation as to be yuite unrecogmsable. The II |