What is a Flower ? 
[October, 
488 
small quantities. The green of summer foliage is the pri- 
mary green of the speCtrum with small additions of red and 
violet, producing yellow or blue greens. 
The colours of the stems and branches of trees and 
shrubs are generally browns and greys ; the foliage is green , 
and the flowers are yellows , pinks , and blues. In terms of 
the absorption of light these faCts mean that in the stem 
and branches all the rays are absorbed, very little being 
reflected, violet least of any; that in the leaves two of the 
primaries are absorbed, while one is reflected ; and that in 
the flowers one primary only is absorbed and two are 
reflected. 
This change of condition in the colouring-matter at the 
three stages of development is in each case in the direction 
of greater concentration and unification. The polychro- 
matic colouring-matter of the stem becomes dichromatic in 
the foliage and monochromatic in the flower. 
The phenomena of light absorption are supposed to de- 
pend upon the molecular condition of the absorbing sub- 
stance. Molecules appropriate the energy of those light-rays 
whose wave-lengths coincide with their own normal vibra- 
tions. In the stems of trees vibrations of all lengths are 
mixed together, and all the light-waves are absorbed. In 
the foliage the vital energy is concentrated in two forms of 
vibration only. In the flower concentration has been carried 
to its extreme limit. White flowers, which in the present 
era are as numerous as all the coloured flowers put together, 
are nevertheless, as flowers, in an embryonic stage. The 
protoplasm, the vital substance, has been exhausted in pro- 
ducing the petalous structure. There is not energy enough 
to fill the cells with living matter. These white-flowered 
species are in arrear of their coloured congeners, but some 
of them will probably in a future epoch attain the higher 
grade. 
It is the special character of the centripetal wave of 
Vital Force to simplify relationships at each successive 
stage of development. This is seen in the external elements 
of a flower as well as in its internal structure. The ar- 
rangement of vascular bundles in the stem is not distinctly 
symmetrical. In the arrangement of leaves, however, there 
is a symmetry more or less evident, while in the flower 
there is a still greater concentration of parts and simplifi- 
cation of arrangement, so that symmetrical relationship is 
a striking feature and one of the main elements of floral 
beauty. 
4. Flowers may exist, and do frequently exist, without 
