218 
THE FLORIST AND POMOLOQIST. 
[ October, 
I 
THE COLOUKING-MATTER OF PLANTS. 
[N all parts of plants -wliicli have a green colour, the cells of -which the 
tissue is composed (and which form the elementary organs of vegetable 
structure) contain certain globular or spheroidal corpuscles, in which the 
green colouring-matter resides. These are called chlorophyll corpuscles, 
and they appear in greater numbers, and of a darker green colour, in proportion to 
the intensity of solar light to which the tissue may be exposed. These corpuscles, 
which are soft bodies, consist of a protoplasmic colourless substance, mixed with 
colouring-matter, which is never found separate in nature. According to Fremy, 
the green colour of chlorophyll is due to an admixture of two substances, one 
yellow, called phylloxanthine^ the other blue, and called phyllocyanine^ though 
other authorities believe the blue substance to be only a modification of the 
yellow, brought about by the agency of acids. Our chemical knowledge of 
chlorophyll is at present incomplete, but it may be expected that spectrum 
analysis will ultimately reveal much of what is now obscure. 
The development of chlorophyll corpuscles is believed to take place thus :— 
In the young cell the protoplasm is colourless, and disposed in a thick layer 
around the inner wall of the cell. Subsequently there appears, first, a yellow 
colouring-matter, and then the inner portion of the protoplasm splits up into 
polygonal portions, each of which becomes a grain of chlorophyll. 
The destruction or decay of chlorophyll shows itself first in a change of colour 
from green to yellow or orange, or in the case of the spores of algae, to red. This 
red colour is assumed at the time when the spores come to rest, and when active 
vegetation recommences the green colour is restored. In the case of leaves, at 
the fall, the grains of chlorophyll diminish, then disappear, and give place to 
highly refractory granules of an orange colour, which are the remnants of the 
disorganized chlorophyll, and to -which the colour of leaves in autumn is due. 
While these processes are going on, the starch and the protoplasm are dissolved 
and stored away in the permanent tissues. In plants kept in the dark, Gris 
noticed that the chlorophyll granules slowly and gradually become smaller and 
lose their starch and colour, till at length nothing but minute amorphous granules 
remain. Some plants, as Selaginellas^ Ferns, &c., bear the deprivation of light 
much better than others, but in all quickly-growing plants, two or three daj^s’ 
obscurity suffices to disorganize the chlorophyll. 
The production of this green matter of plants is a result of the liberation of 
Oxygen. If plants are placed under such circumstances that they cannot decompose 
carbonic acid, and exhale oxygen, as by excluding light from them, they never 
acquire proper development; no green colour appears—they are etiolated ; little 
or no woody matter is formed in the walls of the cells, and the whole energy is 
consumed in pushing out weak, watery shoots. 
The bright colours of flowers are produced by substances usually dissolved 
