The mutation theory; experiments and observations on the origin of species in the vegetable kingdom . m of the curve clearly indicates its participa-tion in the composition of thewhole. In the following year theadvance was much less consid-erable. The maxima at 26 and34 and that near 47 becamemore distinct, but the maxi-mum number of rays increasedto 67. At the same time an-other still more important dif-ference appeared since now forthe first time ligulate floretsappeared between the tubularflorets of the disc. This onlyoccurred on a single plant andnot till the beginning of Sep-tember. This
The mutation theory; experiments and observations on the origin of species in the vegetable kingdom . m of the curve clearly indicates its participa-tion in the composition of thewhole. In the following year theadvance was much less consid-erable. The maxima at 26 and34 and that near 47 becamemore distinct, but the maxi-mum number of rays increasedto 67. At the same time an-other still more important dif-ference appeared since now forthe first time ligulate floretsappeared between the tubularflorets of the disc. This onlyoccurred on a single plant andnot till the beginning of Sep-tember. This plant had 66rays in its terminal inflores-cence, and was one of thosewhich had been selected as seed- l^arents, and accordingly isolated at the beginning of theflowering period. On account of its possession of thisfirst sign of real doubling it was chosen for the continua-tion of the experiment in 1900, to the exclusion of allthe rest. Tt is well known that in other species of this genus(e. g., Chrysaiiflicniuiii ludicum and C. iiiodoniiii) tliedoubling consists in exactly the same phenomenon. In. Fig- 33- Chrysanthemum se-gefiim t>lcnum. One ofthe six inflorescenceswhich in 1899 first exhib-ited true doubHng. Thefigure represents the par-ent plant of the doublevariety. 184 Observation of the Origin of Varieties. the midst of the tubuhir llorets (Fig. 34A) Hgulate floretsare developed (Fig. 34B). If the doubhng is carriedvery far the former are completely covered by the latter(Fig. 34C), and can only be seen by pulling out theligulate florets or by turning them aside. If this is donea large number (and not merely a few scattered ones, asmight perhaps be expected) of tubular yellow corollas
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