THE CHLOROPHYLL-BODIES. 
47 
leaves are red, this depends on a substance dissolved in the sap ; but in this case 
also the yellow granules are to be found. 
The presence of chlorophyll in tissues is not always to be recognised by the 
naked eye. Sometimes the cells that possess chlorophyll contain a red sap ; in 
other cases the green tissue of the leaves is covered by an epidermis with red sap, 
as in young plants of Atriplex hortensis ; in this case, if the coloured epidermis 
be removed, the green tissue may be recognised. But in Algae and Lichens we 
find that the chlorophyll-body of the cell itself contains, in addition to the green 
colouring matter, a red, blue, or yellow substance soluble in water ; the fresh 
Fig. 45.— Chlorophyll-granules of Fiotai-ia hygro-.netrica {X 550). A cells of a mature leaf, seen from the surface ; the clilorophyll- 
granules lie in a parietal layer of protoplasm, in which the nucleus is also imbedded ; they contam starch-grains (left white). B single 
chlorophyll-granule containing starch ; young one, 5 an older one, /?' and <'/' granules in the act of division; c, d, e old chlorophyll- 
g-ranules, the starch-grains of which take up the space of the chlorophyll a young chlorophyll-granule swollen up in water; ^the 
same aft.r long'er action of the water; the clilorophyll is destroyed, the starch-grains which it contained remaining behind. 
chlorophyll-body appears then, by the admixture of the chlorophyll contained in 
it with these substances, verdigris-.£(reen {OsciUaioria, Peliigcra canina, &c.), a fine red 
(Florideae), brown [Fucus, Lammaria saccharind), or buff (Diatomaceae). (See Book 
II., Algs..) 
From this are to be distinguished those cases in which the originally green 
chlorophyll-granules assume a red or yellow colour from the alteration of their 
colouring material, a phenomenon which, from its physiological bearings, I have 
termed Degradation of chlorophyll. Thus the green bodies in the walls of the 
