re multiply also by division, splitting up into two new bodies, each capable 
_ of independent life. 
The parts of plants which are not green, as the petals, have peculiar 
_ pigments in their cells, sometimes dissolved, sometimes as solid particles. 
Particles of a red pigment are found, for example, in Adonis autumnahs, 
0'004 mm. in diameter, of an orange colour in Zinnia elegans, yellow in 
an | ‘ 
a athe San a Wei Fic. 41.—Band of chlorophyll in 
—_ 350.) 
Fic. 40.—Cells from the leaf of Vadllrs- 
neria spiralis, ‘The round bodies are 
grains of chlorophyll ; the arrows denote 
the direction of the currents of proto- 
plasm. (x 800.) 
Kerria japonica. A violet colour is always, a blue colour usually, due 
to dissolved pigments. As an example how peculiarly the separate 
pigments may be distributed in different superimposed layers of cells, 
the marginal flowers in the capitulum of Zzvza elegans are scarlet on the 
_ upper, light yellow on the underside, the uppermost layers of cells con- 
tain a purple sap with orange granules, all the rest a colourless sap 
_ with a smaller number of light yellow granules. Only those cells which 
are filled with air appear white ; a black appearance depends on a dark 
shade of a violet or brown colour. The conditions which favour the» 
formation of the bright pigments are not yet known; the agency of 
T he Cell as an Individual. vee : 25 
Spirogyra (Conjugate): two | 
cells seen from the surface. (x — 
