The Sleeping of the Fields 



of Plants," has observed that in 

 autumn the cell-contents of the 

 leaves about to fall are changed into 

 soluble substances, and these are 

 conveyed to the permanent parts of 

 the plant. The protoplasm, or clear 

 leaf-jelly, disappears, and so do the 

 little green chlorophyll corpuscles 

 which float in it. 



" I was able," says Professor Von 

 Sachs, " by microchemical methods, 

 to follow distinctly the travelling 

 of the materials (especially of the 

 starch) out through the tissue of 

 the leaf-stalk into the shoot-axes. 

 Moreover, the ash-analyses of sum- 

 mer leaves, compared with those of 

 autumn ones, show that the most 

 valuable mineral constituents of the 

 leaves, especially the potash and 

 phosphoric acid, also pass out, 

 through the leaf-stalks, back into 

 the parts of the bough which sur- FIG. 99^. Leaf-scar 



of thehorse-chest- 



vive the winter. nut, showing the 



cork-seal studded 



By time the leaves fall the cells with the blackened 



ends of fibro-vas- 



of their tissues contain little else cular bu n dies. 



(Magnified.) 



