498 APPENDIX. 



jections raised by the present writer and others, and examines some 

 of the alleged exceptions.' Some of these the Belgian savant finds to 

 prove his loile, inasmuch as although there is a co-existence of varie- 

 gated foliage and double flowers in these illustrations, yet the plants 

 are weakly, the flowers ill fonned, or fall off b'efore expansion. 

 Admitting all this, there still remain cases in which double flowers 

 and vaiiegated foliage do exist in conjunction, and where the plants 

 are vigorous and the flowers well developed. Instances of this ax*e 

 known to cultivators in species of Dianthus, Hemerocallis, AUhaa, 

 Pceonia, Rosa, Ranunculus, Serissa, Saponaria, etc., and probably the 

 art of the cultivator would speedily be successful in luising other ex- 

 amples, were it a matter of importance or interest to them to do so. 

 At any rate, the existence of a few unimpeachable illustrations is 

 sufficient to support the opinion of the present wi'iter, and objected to 

 80 strongly by M. MoiTcn that, in the present state of our knowledge, 

 "no safe inferences can be di'awn" from the facts alluded to by the 

 Belgian professor.* 



Mr. Dai'win'-* has thrown out the suggestion that the cause for the 

 appeai'ance of double flowers may be sought for in some previous state 

 of things, bringing about sterility or imperfect formation, or functional 

 activity of the genitalia of the flower, and consequent compensatory 

 increase of the petaline element, either in the form of an increased 

 number of bracts, petals, &c., or in the substitution of petals for stamens 

 and pistils, &c. 



In considering these points the question arises whether they can be 

 reconciled one with another. And thei'e is little doubt but that they 

 may be. The production of a flower is preceded by an aiTCst of vege- 

 tation ; this is obvious : the current of the plant's life becomes changed, 

 the gi'owth of the leaves is checked, the lengthening of the branches is 

 arrested as the flower-bud forms ; moreover, there is a close relationship 

 in a large majority of flowers between the outer envelopes of the flower 

 and the scales of a leaf-bud ; this is especially so in regard to the vena- 

 tion, and is admitted by all morphologists. So far, then, it may be 

 said that the production of a flower, like that of a bud, is due to a 

 diminution of vegetative action ; and as in double flowers we have, for 

 the most part, merely a repetition and exuberant formation of floral 

 envelopes, so we may attribute their fonnation to a continuance of the 

 same feeble vegetative action as that which produced the first or normal 

 series. How, then, can a copious supply of rich food, such as is pro- 

 vided by cultivation, produce double flowers ? To this question, accord- 

 ing to our theory, the reply would be that the quantity of food is 

 excessive, more than the plant can properly digest ; and hence vegeta- 



See ' Gardeners' Chronicle/ 1868, p. 1113. 

 ' Ibid., 1843. p. 628. 



