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Show 196 . DARWINIAN A. se l ecuo~(n') on. The former has n.e ver yet b))e en shown to. h ave I'ts cause in "external mfluences,. n. or dt o 'fo ccm a t ran d om. As We have elsewhere . msiste , 1 not inexplicable, it has never been explamed ; all we can yet say is , that plants and animals. ar. e propn e tho vary. , and that some conditions favor vanatiOn. er aps m thI.S D r. Falconer may yet find wha. t he .s eerk. s:J for " it is difficult to believe that there IS not m Lits na-t e a deeper-seated and innate principle, to the operatiuorn of which natural selection is merel y an ad "J Unc~. " The latter, which is the ensemble of the e:te~n~l mfluences including the competition of the Individuals themsel~es, picks out certain var~ations .a~ they arise, but in no proper sense can be said _to or1gmate them. 2 Although we are not quite sure how Dr. Falc~ner intends to apply the law of phyllotaxis to illustrate his idea, we fancy that a pertinent illustration may be drawn from it, in this w_ay: There are two species of phyllotaxis, perfectly distmct, and, we suppose, not mathematically reducible the. on~ to t~e other, viz. : (1.) That of alternate leaves, With Its. vaneties;. and (2.) That of verticillate leaves, of which opposite leaves present the simplest case. T~at, although generally constant, a change from one vanety of alternate phyllotaxis to another should occur. o~ the sa~e axis or on successive axes, is not surpnsmg, the differe~ t sorts being terms of a regular series-although, indeed, we have not the least idea as to how the ch~n~e from the one to the other comes to pass. . But I~ 18 interesting, and in this connection perhaps Instructrve, to remark that, while some dicotyledonous plants hol~ to the verticillate, i. e., opposite-leaved phyllotaxis SPECIES AS TO VARIATION, ETC. 197 throughout, a larger number-through the operation of some deep-seated and innate principle, which we cannot fathom-change abruptly into the other species at the second or third node, and change back again in the flower, or else effect .a synthesis of the two species in a manner which is puzzling to understand. Here is a change from one fixed law to another, as unaccountable, if not as great, as from one specific form to another. An elaborate paper on the vegetation of the Tertiary period in the southeast of France, by Count Gaston de Saporta,· published in the .Annales des Sciences Naturelles in 1862, vol. xvi., pp. 309-344-which we have not space to analyze-is worthy of attention from the general inquirer, on account of its analysis ·of the Tertiary flora into its separate types, Cretaceous, Austral, Tropical, and Boreal, each of which has its separate and different history-and for the announcement that "the hiatus, which, in the idea of most geologists, intervened between the close of the Cretaceous and the beginning of the Tertiary, appears to have had no existence, so f~r as concerns the vegetation; that in general it was not by means of a total overthrow, followed by a complete new emission of species, that the flora has been renewed at each successive period; and that while the plants of Southern Europe inherited from the Cretaceous period more or less rapidly disappeared, as also the austral forms, and later the tropical types (except the laurel, the myrtle, and the O~a~Cl3rops huntilis), the boreal types, coming later, survived all the others, and now compose, either in Europe, or in the north of Asia, or in North America, |