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Show 886 llUD VARIATION CHAP. XI. Byblocmcns and some other kinds have been raised from scvcml distinct breeders, yet all the Bagucts are said to have come from a single breeder or seedling. 'l'h:is bud-variation, in accordance with the views of MM. Vilmorin and Verlot,ro is probably an attempt to revert to that uniform colour which is natural to tho species. A tulip, however, which hn,s already b como broken, when treated with too strong manure, is lin,blc to flush or lose by a second act of reversion its variegated colours. Some kinds, as Impcratrix Florum, arc much more liable thn,n others to flushing; ancl Mr. Dickson mrtintains 80 thu.t this can no more be accounted for than tho variation of n,ny other plant. He believes that English growers, from care in choosing seed from brok n flowers ilJstcacl of fl'om plain flowers, have to a cor1rtin extent diminished tho tendency in flowers already broken to flushing or . · condary reversion. Dnring two conSCClltivo years an the crtrly flowers in a bed of Tigr-irtia couc/uj!OI'C£ Sl rOSCm uled t ltOSC Of tliC old '/ '. J!UU011 ic£ i hut tho later flowerS assumed their proper colour of fino yellow spotto<l with crimson. .An apparently authentic account has been pnhUshed 82 of two forms oCIIcmewrn, llis, which have boon universally considered as uistinct species, changing into each oLhcr; for tl10 roots of the lrLrgc-flowcred tawny J!.fulurr, being divided and plrtntcd in a different soil and place, produced the smn,llflowcr d yellow 1 I. jlrwn, as well as some intermediate forms. It is donbt ful wl10thor Ruch: cases as these latter, as well as tho "flushing" of brok 'n tulips and tho "running" of prtrticolourcd crtmations,-tl1at is, thou· more or loss complete return to a uniform tint,-ought to bo clas eel under bucl-variation, or ought to he retained for tho chapter in which I trent of tho direct action of the conditions of lifo on organic beings. These cases, however, have this much :in common with bud-vn,riation, that tho cha11go is effected through buds anti. not through seminal reproduction. But, on tho other hancl, thoro is this difforonco-thn,t in orclinn,ry oases of lmuvariation, one bucl alone changes, whilst in tho foregoing cases all tho bnds on the same plant wore modified together; yet wo have an intermediate case, for wW1 tho potato all tho eyes in one tuber alone simultaneously changed their character. I will oonoh1 lo with a few allied cases, which may be ranked either under lmcl-variation, or under tho direct action of tho conditions of life. When tho common Hepatica is transpbntod from its native woods, tho flowers chango colour, oven during tho first yoar.83 It is notorious tlw,t the improved varieties of tho Ucartsoaso ( V'iola tricolor-) when tnmsplantcd often procluco flowers widely different in size, form, and col om: for instance, I transplanted a largo uniformly-oolomecl clark purple variety, whilst in full flower, and it then produced much smaller, more elongated flowers, with tho lower petals yellow; those woro succoodod by flowers maT ked with largo purple spots, and ultimately, towards tho end of the same summer, by tho original largo dark purple flowers. Tho slight changes which some 10 'Prouuction c1cs Vurielcs' 18G5 p. G3. ' ' 80 'Gartl. Chron.,' 1811, p. 782; 1842, p. 55. ' 81 'Garcl. Chron.,' 18·1D, p. 5G5. 82 ' 'l'mns:.wt. Linn. Soc.,' vol. ii. p. 3M. 83 G ouron, ' De l'Especc,' tom. ii. p. 84. CrrAI'. XI. BY SUCKERS, TUBERS, AND BULBS. 387 fru~t-troos .undergo from being grafted and rcgraftod on various stocks,s' wore considered by Andrew Knight 85 as closely allied to "sporting bmnch.o s ' " or .b ud- va n·a t w' ns. A gam· , we have the cn,se of young fruit-trees ohangJ.ng thorr ~har~otor as they grow old; seedling pears, for instance, l~~e Wl~h age thmr spr.nes ancl improve in tho flavour of their fruit. Weeping buch-trcos, wh?n grafted on the common vaTiety, do not acquire a perfect ~?ndulous hn,b1t until they grow old: on the other hand, I shall hereafter gtvo t~?,.,. case o~ some weeping rtshcs which slowly and gradually assumed an upuoht l~ab1t of growth. All such changes, dependent on age, may bo comparocl WJth tho changes, alluclcd to in tho last chapter which many trees :o.aturall_Y unclorgo; rts in tho case of tho Deodar ~nd Cedar of Lebanon, wluch a.ro unlike in youth ancl closely resemble each other in old age; :mel as w1th certain oaks, and with some varieties of the lime and hawthorn.80 . Before giving a summary on Burl-variation I will discuss some smgular anc~ anomalons cases, which are more or less closely related to this ·ame subject. I will begin with the famons case of A:lam's laburnum or O!jtisus Adami, a form or hybrid intermediate between two very distinct species, namely, 0. laburnum ancl purpu1·eus, the common ancl purple laburnum; but as this tree has often been described, I will be as brief as I can. Throughout ~mope, in different soils ancl under different climates, branches o~ t~ns tr?e have repon,todly and suddenly reverted to both parcnt-spocJoR. m thOJr flowers anclloavos. To behold mingled on the s::Lme tree. tufts.of clm~y.-rod, bright yellow, and purple flowers, borne on branches ~avmg Wlucly dJJiorcnt l.cavcs and manner of growth, is a surprising sight. ~he same raceme sometimes bears two kinds of flower.·; and I have seen a smglc flower exactly divided into halves, one side being bright yellow ancl tl~o other purple; so that one half of tho standn,rd-petal was yellow ancl of larger s1ze, and the other half purple ancl smaller. In another flower the whole corolla was bright yellow, but exactly half tho calyx was pmplo. In .another: one of the dingy-rod wing-petals had a bright yellow narrow str1po on .1t; and l~stly, in another flower, one of the stamens, which hacl become slightly foli~ceouR, was half yellow ancl half purple; so that tho tendency to segregatiOn of character or reversion affects oven single parts • 84 M. Carriero has lately describcu, m the 'Revno Ilorticolo ' (Dec. 1, lSGG, ~ · 457), an cxtrMrdinary case. He twice Inserted graf'Ls of tho .1h·ia 'Cestita on th orn-trees ~epines) growing in pots ; anll the ~rafts, as they grew, proclurcd shoots wtth hark, bud~, leave.;, pctiolrs, ~etals, allCl flower-stalks all widely different from those of the AI·ia. The grnftcd shoots were also much hardier an<l flowered earlier, than those on tlt~ UIIgr:.&JtuJ Aria. 85 'Transact. Hort. Soc. ' vol. ii p 1G0. ' . . 86 For t~te cases of onks see Alph. Do CanJolle m 'Bib!. Univers.,' Geneva Nov. 18G2; for limes, &c., Loudon'~ • Gurd. Mag.,' vol. xi., 1835, p . 503. 2 c 2 |