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Show 382 DUD-VARIATION. CUAP. XI. on a dinO'y-purplo, double vn.rioty of tho wall-flower ( Oheiranthus che£ri) a branch which had reverted to tho ordinary copper colom. On other branches of tho same pln.nt, some flowers were exactly divided across the middle, one ha.lf being pmplo and tho other coppery; but some of t~o smaller petals towards tho centro of these same flowers were pu~·ple longitudinally streaked with coppery colour, or coppery strcakcdw1th p~uplo. A Cyclamen 62 has been observed to bca1· white and piJ1lc flowers of two forn:s, tho one resembling tho Pcrsicnm strain, n.nd tho .other tl:o Coum sham. Oenothem bien11 is has been s •en "3 bearing flo weTs o[ tlu·cc different colours. The hvbrid Ulwliollls coluilfii occasionn.lly bears uniformly coloured flowers, and o'no case is recorded 5·1 of all tho flowers on a pl::tnt thus changing colour. A Fnclmin. Jms been seen"" bcn.ring two kinds of flowers. JJ!Jirubilt:s y'ula7Ja is eminently Sl)Ortivo, sometimes bcar.ing on tho_ same roo~ pu_ro red, yellow, and wl1ito nowors, and others striped witl; vn.n?us combmatwns of thc:o tln·co coloms.or. The plants of tho Mirahihs wluch bear su~h o~t~aonlinn. rily va.ri:Ll1lo flowers, in most, probal1ly in all cases, owe tbcn_or~gm, as shown by l)rof. Lccoq, to crosses between clifl"crcntly-coloured vanct10s. J:caves ancl Shoots.-Changos, through bud-variation, in fruits and ilo:wers have hitherto b en treated of, but incidentally Rome r markablo modifications in tho leaves and shoots of tho rose a11d Cistus, and in a lesser degree in tho foliage of tho Polargonium n.nd _Ch:rys~nthc~um, have bee~ noticed. I will now add a few more crtscs ofvrmatwn m leaf-buds. Vcrlot states that on ./lrali(t tnfolinta, wl1ich J)roporly has leaves with three leaflets, branch s bcn.ring simple leaves of various forms frcCJ:ucntl~ appear; these can be propagntcd by buds or gmftiJ1g, and have g1ven nse, as ho states, to several nominal sp cics. . . With rc ·poet to trees, tho history of but few of tho many vancbes with curious or ornamental foliage is Jmown; but several probably hn.vo originated by bud-variation. licrc is one case :..L..A.n old ash-tree (Fr-axi'11us errcelsior) in tho grounds of Nccton_, ~s Mr. Mason states, "for many years has had one bough of a totally d1ffcrcnt character to the rest of the tree, or of any other a!:ilt-treo which I have seen; being short-joir:tcd and densely covered with foliage ." It was ascertained that this vanety could bo propan·atcd by grn,fts.58 Tho varieties of some trees with cut leaves, as tho oak-leaved laburnum, the parsley-leaved vine, and asp cially tho fern-] avcd beech, arc apt to revert by bnd: to the common form. 5 9 'l'hc fern-like leaves of the beech somctim s revert only partially, and tho branches clispla.y hero and there sprouts bearing common leaves, fern-like, and variou!:ily !:ihapcd leaves. Such cases diil'cr but little from the so-called s~ 'Gm·d. Chron.,' 1807, p. 235. 53 Gurtner, 'I3asLun1crzcugung,'s. 305. 51 1\'Ir. D. I3 nLon, in 'UoLtago Gar-donor,' 1 60, p. 250. ar. 'Gard. Cl1ron.,' 1850, p. 53G. 56 J3rnun, ' Hay Soc. Bot. 1\fem.,' 18:)3, p. 315 ; llopki rk's 'Flora A nomala,' p. 1G4; Lccoq, 'Gcogn.t].Jh. I3ot. de l'Europe,' tom. iii., 1854, p . 4.05; and 'Do la Fccond1LLion,' 1862, p. 003. 87 • Des Vruiclcs,' 1805, p. 5. ss W. 1\'Iason, in' Guru . Chron.,' 1843, p. 878. 59 Alex. I3raun, 'Ray Soc. llot.l\fem.,' 1853, p . 315 ; 'Ganl. CLrou.,' 18.J.l, P· 329. CHAP. XJ. LEAVES AND SIIOOTS. 383 hotorophyllous varieties, in which tho tree habitually bears leaves of various forms; but it is probable that most hotcrophyllous trees have originated as seedlings. Thoro is a sub-variety of tho weeping willow with leaves rolled np into a spiral coil; and Mr. Masters states that a tree of this kind kept true in bis garden for twenty-five years, and then threw out a single upright shoot bearing flat leavos.Go I have often noticed single twigs and branches on beech and other trees with their leaves fully expanded before those on tho other branches had opened; and as there was nothing in their exposure or character to account for this difference, I presume that they had appeared as budvariations, like tho early and late fruit-maturing varieties of tho peach and ncctal'ino. Cryptoga.rnic plants arc liable to bud-variation, for froncl.f; on tho same fern arc often seen to display rcmarlmblo deviations of structure. Spores, which arc of tho nature of buds, taken from such abnormal fronds, reproduce, with remarkable fidelity, tho same variety, after passing through tho sexual stagc.r.1 With respect to celom, loaves often become by bud-variation zoned, blotched, or spotted with white, yellow, and rod; and this occasionally occms even with plants in a state of nature. Vari gation, however, appears still more frequently in plants produced from seed ; oven tho cotyledons or seed-loaves being thus aff'cctcd.62 Thoro have been endless disputes whether variegation should be considered as a disease. In a futuro chapter we shall sao that it is much influenced, both in the case of seedlings and of mature plants, by the nature of tho soil. Plants which bavo become variegated as seedlings, generally transmit their character by seed to a largo proportion of their progeny; and Mr. Salter has given me a list of eight genera in which this occurrocl..63 Sir F. Pollock has given me more precise information: ho sowed seed from a variegated plant of 1Jullotc1 nigt·a which was found growing wild, and thirty per cont. of tho seedlings were variegated; seed from these latter being sown, sixty per cent. came up variegated. When branches become variegated by bud-variation, and tho variety is attempted to bo propagated by seed, tho seedlings arc rarely variegated; Mr. Salter found this to be tho case with plants belonging to eleven genera, in which tho greater number of tho seedlings proved to be green-leaved; yet a few were slightly variegated, or were quito white, but none were worth keeping. Variegated plants, whether originally produced from seeds or buds, can generally be propagated by budding, grafting, &c.; but all arc apt to revert by bud-variation to their ordinary foliage. This tendency, however, differs much in the varieties of even the same species; for instance, the golden-striped variety of Euonymus Japon£cus "is very liable to run back to tho green-leaved, while tho silver-striped r.o Dr. M. T. Mnstcrs, 'Royal Institution Lecture,' March 16, 1860. Gl See Mr. W. K. IJriJgmnn's curious paper in' Annnlsund Mag. of Nat. Irist.,' December, 18Gl ; also Mr. J. Scott, 'Dot. Roc. Edinbmgb,' Juno 12, 1802. 62 'Journal of Horticulture,' 186L, p. 33G; Verlot, • Des Varictcs,' p. 7G. 6: 1 See also Vcrlot, 'Des Varictcs,' p. 74. |