THE CHL OR OPHYLL- B ODIES. 



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 Airiplex 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 







^^^H( 550). A in the middle, B at the margin ; ch the chlorophyll-granules ; visible 

 ^^^K them are the small starch-grains; eu the lower epidermis; eo the upper 

 ^^^■udermis ; / an air-conducting intercellular space ; sp stomata. 



m 



Fig. 45.— Chlorophyll-granules of Ftinaria hygrovtetrica {X 55°)- ^ cells of a mature leaf, seen from the surface ; the chlorophyll- 

 granules He in a parietal layer of protoplasm, in which the nucleus is also imbedded ; they contain starch-grains (left white). B single 

 chlorophyll-granule containing starch ; a a young one, 5 an older one, 5' and *" granules in the act of division ; c, d, e old chlorophyll- 

 granules, the starch-grains of which take up the spaci of the chlorophyll ; y a young chlorophyll-granule swollen up in water ; i.'- the 

 same after longer action of the water; the chlorophyll 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-green {Oscillatoria^ Feliigera canina, &c.), a fine red 

 (Florideae), brown {Fucus, Laminaria saccharina), or buff (Diatomacese). (See Book 

 11., Algee.) 



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 



