4.98 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 rule, 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 formed, or fall off before expansion. 
Admitting all this, there still remain cases in which double flowers 
and variegated foliage do exist in conjunction, and where the plants 
are vigorous and the flowers well developed. Instances of this are 
known to cultivators in species of Dianthus, Hemerocallis, Althea, 
Peonia, Rosa, Ranunculus, Serissa, Saponaria, etc., and probably the 
art of the cultivator would speedily be successful in raising 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 writer, and objected to 
so strongly by M. Morren that, in the present state of our knowledge, 
“no safe inferences can be drawn” from the facts alluded to by the 
Belgian professor.’ 
Mr. Darwin? has thrown out the suggestion that the cause for the 
appearance 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 there is little doubt but that they 
may be. The production of a flower is preceded by an arrest of vege- 
tation ; this is obvious: the current of the plant’s life becomes changed, 
the growth 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 ofa 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 formation 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- 
1 See ‘ Gardeners’ Chronicle,’ 1868, E. 1115. 
* Thid., 1843, p. 628. 
