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Show 78 DARWINISM CHAP. remarkable factR n.s to their va.rin.bility. He declares ~h~t on the same brn.nch of oak he has noted tho following :varw.t10m; : (1) In the length of the pc~io~c, as one to t.hrce j (~) m tho.f~,:~n of the leaf, being either elliptical or o~ovoH~; (3) m ~he m;1.1gm bcino- entire, or notched, or even pmnatrfid j ( 4) J.n tho extremity bcino- acute or blunt j (5) in the base bcmg sharp, blunt or co~'date; (6) in tho surface being pube~ccnt or smooth; (7) the perianth varies in depth and lobmg; (8) the stamens vary in number, independently; (9) the anthon; are mucronate or blunt; (1 0) tho fruit stalks vary grca~l y in lenoth often as one to three j (11) the number of frmLs varies 7 (i 2) the form of the base of the cup varies.; (13) the scales of the cup vary in form; (14) the pro~ortwns of ~h e acorns vary j (15) the times of the acorns npemng and fallmg vary. . . . . . Besides this, many species exhibit well-marked vanetiCs which have been described and named, and these are most numerous in the best-known species. Our British oak (Quercus robur) has twenty-eight varieties; Quercus Lusitanica. ha.s eleven ; Quercus calliprinos has ten j and Quercus coccifcm eight. A most remarkable case of variation in the parts of n. common flower has been given by Dr. Hermann M'lillcr. IIo examined two hundred flowers of Myosurus minimus, among which he found thirty-jive different proportions of the sopalR, petals, and anthers, the :first varying from four to seven, ,~he second from two to :five, and the third from two to ten. bvc sepals occurred in one hundred and eighty-nine out of the two hundred but of these one hundred and five had three petn ls, forty-six' had four petals, and twenty-six bad :five petals; but in each of these sets the anthers varied. in number from t l n'('(' to cio·ht or from two to nine. \V c have here an example of b ' the same amount of "independent variabjlity" thn.t, a.s we have seen occurs in the various dimensions of birds and mammals; and it may bo taken as an illustration of the kiJHl and degree of variability that may be expected to occnr among small and little specialised flowers. 1 In the common wind-flower (Anemone nemorosa) an almost equal amount of variation occurs; and I have myself g<.~Lhered 1 Nature, vol. xxvi. p. 81. lli VARIABILITY OF SPECIES IN A S'l'ATE OF NATURE 79 ir~ one locality flowers varying from A- inch to 1J inch in <lmmetcr ; the bracts varyincr from 1 i inch to 4 inches aero •, ; ~nd the petaloid sepals oithc.l' broad or narrow, and varying m number from :five to ten. Though generally pure white on their upper surface, , orne specimens are a full pink, while others have a decided bluish tinge. Mr. Darwin states that he carefully examined a larrro number of plants. ~f Geranium phmum and G. pyrenaicum (not perhaps truly Bn~L h. but frequently found wild), which had escaped f~'Om cultivatiOn, and had sproa.d by seed in a.n open pbntn,tlon j and he declares that "the seedlings varied in almost every single character, both in their flower. and foliaae, to n. degree which I have never soon oxcoedcd; yet they could not have been exposed to any great chango of their conditions. "I The following examples of variation in important parts of plants wore collected by Mr. Darwin and have boon copied from his unpublished MSS. :- "De Candollo (Mem. Soc. Phys. de Geneve, tom. ii. part ii. p. 217) states that Papaver hmctoatum and P. orientale present indifferently two sepals and four petals, or throe sepals a.nd six petals, which is sufficiently rare with other species of the genus." "In the Primulacero and in the great class to which this family belongs tho unilocular ovarium is free, but M. Dubury (Mem. Soc. Phys. de Geneve, tom. ii. p. 406) has often found individuals in Cyclamen hcdermfolium, in which the base of the ovary was connected for a third part of its lenath with the inferior part of the calyx." 0 "M. Aug. St. Hilaire (Sur la Gynobase, Mem. des M'lts. d'Hist. Nat., tom. x. p. 134), speaking of some bushes of the Gomphia olerofolia, which he at first thought formed a quite distinct species, says : 'Voila done dans un meme individu dos loges et un style qui se rattachent tantOt a un axe vertical, et tantot a un gynobase j done colui-ci n'est qu'un axe veritable j mais cet axo est deprime au lieu d'etro vertical." He adds (p. 151 ), 'Does not all this indicate that nature has tried, in a manner, in the family of Rutacem to produce from a single multilocular ovary, one-styled and symmetrical, several unilocular ovaries, each with its own style.' And he 1 A nim,als and Plants under Dornest·ication, vol. ii. p. 258. |