CELLS. 
27 
of crimson fluid, which imparts to this favourite flower 
its rich hue. In the case of the ferns before alluded 
to, the brown colour depends on that of the cell-wall, and 
not on its contents. In old cells of Palms and certain 
Coniferm, resinuous matter of rich colour is often met 
with ; this, however, is solid, and is very remarkable in 
the palm yielding the substance called dragon’s blood. 
The green colour, so universally present in plants, is due 
to a more or less solid material, contained in cells and 
termed chlorophylle, or green vegetable wax ; it consists 
of minute spherical or oval particles, but as these have 
certain properties in common with starch, they will be 
more particularly described with that substance. 
