622 APPENDIX G. 



stocks which have not yet flowered, those which will produce 

 double flowers are distinguishable. He says: 



" This separation of the single from the double-flowered plants, M. Chatie 

 tells us is not so difficult as might be supposed. The single stocks, he ex- 

 plains, have deep green leaves (glabrous in certain species), rounded at the 

 top, the heart being in the form of a shuttlecock, and the plant stout and 

 thick-set in its general aspect, while the plants yielding double flowers have 

 very long leaves of a light green colour, hairy and curled at the edges, the 

 heart consisting of whitish leaves, curved so that they enclose it com- 

 pletely." 



What is the general truth implied ? Clearly that there exists 

 no such thing as an independent local variation. Some marked 

 change in the form or colour of a flower or a fruit draws atten- 

 tion ; and, being a change which interests the florist or gardener, 

 pecuniarily or otherwise, not only draws attention but usually 

 monopolizes attention : the natural impression produced being that 

 this variation stands there by itself is without relation to 

 variations elsewhere. But now it turns out that there are 

 concomitant variations all over the plant. Even in under- 

 ground bulbs certain appreciable differences go along with certain 

 conspicuous differences in the flowers. And if along with a 

 striking change in a flower which the florist contemplates, there 

 go changes all over the plant not obvious to careless observers 

 but visible to him, we must infer that there are everywhere 

 minute differences which even the florist cannot perceive: the 

 whole constitution of the plant has diverged in some measure 

 from the constitutions of kindred plants. Every local variation 

 implies a change pervading the entire organism, manifested in 

 concomitant variations everywhere else. 



If so, what becomes of the hypothesis of determinants the 

 hypothesis that there is a special element in the germ-plasm 

 which results in a special local modification in the adult organism ? 

 That there are no facts supporting it has been all along mani- 

 fest ; but now it is manifest that the facts directly contradict it. 



At the same time it may be remarked that while the facts are 

 wholly incongruous with the hypothesis of determinants and its 

 accompanying elaborate speculation, they are not incongruous 

 with the alternative hypothesis. Impossible though it may be 

 to imagine the natures of those ultimate units peculiar to each 

 species, which have proclivities towards the particular form 

 of organization characterizing it, yet that a change of structure 

 arising in one part of the organism is accompanied by multitudi- 

 nous changes of structure in other parts of the organism, is not 

 only congruous with the belief that there exist such constitutional 

 units, but yields it distinct support. For if, as above argued, a 

 conspicuous local variation is not the result of any modification of 

 units special to the locality, but is the result of a modification of 



