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Show 64 INHERIT ANCR CHAP. XliT. these same characters now vary under domestication, or fail to be inherited, owing to their lesser antiquity. But we must believe structures which have already varied, would be more liable to go on ~arying, rather than structures which durin? an immense lapse of time have remained unaltered ; and tlus variation is probably the result of certain 1:elat~ons between the conditions of life and the organisation, qmte mdependently of the greater or less antiquity of each particular c~arac.ter. Fixedness of character, or the strength of mhentance, has often been judged of by the preponderance of certain characters in the crossed offspring between distinct races ; but prepotency of transmission here comes into play, and this, as we shall immediately see, is a very different consideration from the strength or weakness of inheritance. It has often been observed 1 that breeds of animals inhabiting wild and mountainous countries cannot be permanently modified by our improved breeds; and as these latter are of modern origin, it has been thought that the greater antiquity of the wilder breeds has .been the c.au~e of their resistance to improvement by crossmg; but It IS more probably due to their structure a~~ constitution being better adapted to the surrounding conditiOns. When pla?ts are first subjected to culture, it has been found that, dun~g several generations, they transmit their characters truly, that IS, do not vary, and this has been attributed to ancient characters being strongly inherited; but it may w~t~ equal. or gr~a.ter probability be consequent on change~ conditiOn~ of hfe r.equmng a long time for their accumulative actwn. Notwithstandmg these considerations, it would perhaps be rash to deny that characters become more strongly fixed the longer they are transmitted; but I believe that the proposition resolves itself into this, -that all characters of all kinds, whether new or old, tend to be inherited, and that those which have already withstood all counteracting influences and been truly transmitted, will, as a general rule, eontinue to withstand them, and consequently be faithfully inherited. 1 See Youatt on Cattle, pp. 92, 69, 78, 88, 163 : also Youatt on Sheep, P· 325. Also Dr. Lucas, • L'Hered. Nat.,' tom. ii. p. 310. CHAP. XIV. PREPOTENCY OF TRANSMISSION. 65 Prepotency in the Transmission of Ch.aracter. When individuals distinct enough to be recognised, but of the same family, or when two well-marked races, or two species, are crossed, the usual result, as stated in the previous ebapter, is, that the offspring in the first generation are intermediate between their parents, or resemble on~ parent in one part and the other parent in another part. But this is by no means the invariable rule; for in many cases it is found that certain individuals, races, and species are prepotent in transmitting their likeness. This subject has been ably discussed by Prosper Lucas,2 but is rendered extremely complicated by the prepotency sometimes running equally in both sexes, and sometimes more strongly in one sex than in the other; it is likewise complicated by the presence of secondary sexual characters, which render the comparison of mongrels with their parent-breeds difficult. It would appear that in certain families some one ancestor, and after him others in the same family, must have had great power in transmitting their likeness through the male line; for we cannot otherwise understand how the same features should so often be transmitted after marriages with various females, as bas beentbe case with the Austrian Emperors, and as, according to Niebuhr, formerly occurred in certain Roman families with their mental qualities.3 The famous bull Favourite is believed 4 to have had a prepotent influence on the shorthorn race. It has also been observed 5 with English race-horses that certain mares have generally transmitted their own character, whilst other mares of equally pure blood have allowed the character of the sire to prevail. The truth of the principle of prepotency comes out more clearly when certain races are crossed. The improved Shorthorns, notwithstanding that the breed is comparatively modern, are generally acknowledged to possess great power in impressing their likeness on all other breeds; and it is chiefly in consequence of this power that they are so highly valued 2 'Hen~d. Nat.,' tom. ii. pp. 112- 120. 3 Sir H. Holland, 'Chapters on Mental Physiology,' 1852, p. 234. · VOL. II. 4 'Gardener's Chronicle,' 1860, p. 270. s :M:r. N. H. Smith, Observations on Breeding, quoted in ' Encycl~p. of Rural Sports,' p. 278. F |