THE CHLOROPHYLL-BODIES. 



47 



consideration of these and of numerous other purely physiological properties of 

 chlorophyll must be deferred till then. Sooner or later, in the normal course of 

 things, the chlorophyll-bodies are again absorbed ; this occurs in the most conspi- 

 cuous manner at the time when the leaves of the higher plants are preparing for their 

 fall; for instance, in the case of our native trees and shrubs, in the autumn. Here 

 the whole mass of protoplasm, — and with it the chlorophyll-bodies from the cells 

 of the leaves destined to fall, — is absorbed, and transferred to the perennial parts; 

 the appearances which then present themselves are very different ; but finally there 



Fig. 46, — Transverse section tliroutrh the \>i3.( oi Sclacrinella inaquatifolia 

 (X550). A in the middle, />'at the margin ; ch the grains of chlorophyll ; visib 

 in them arc points, the small granules of starch ; en the lower epidermis 

 eo the upper epidermis ; / the air-conducting intercellular space ; sp stomata. 





Fig. 47.— Chlorophyll-grains ol Funaria hygr07ttetrica (X550). A cell of a mature leaf, seen from the surface; the parietal chlo- 

 rophyll-grains lie in a layer of protoplasm, in which the nucleus is also imbedded; the chlorophyll-grains contain starch grains (teft 

 white). B single grains of chlorophyll containing starch ; a a young one, b an older one, b' and b" grains in the act of division ; c, d, e 

 old chlorophyll-grains, the starch granules of which take up the space of the chloropliyll ; f a young chlorophyll-grain swollen up in 

 water ; s; the same after longer action of the water ; the chlorophyll is destroyed, the starch-granules remaining behind. 



remain in the cells filled with water and often containing pointed crystals, a number 

 of yellow glittering granules which have no similarity to chlorophyll ; if the falhng 

 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 in the colouring of the organs. Sometimes the cells that possess 

 chlorophyll themselves contain a red sap ; in other cases the green tissue of the 

 leaves is covered by an epidermis provided with red sap (young plants of Atriplex 

 hortensis) ; in this case, if the coloured epidermis be removed, the green tissue may 

 be readily reco":nised. But in Al^se and Lichens we find that the chlorophyll- 



