THE LEAF m 



After this exposition we shall not be surprised to find that 

 nature has arranged these chief formative organs in such a 







Fig. 15.— Surface View and Section of the Leaf of the Bakley. 

 E, a piece covered by the epidermis ; F, portion from whicli the epidermis has been 

 stripped ; o, long, thin-walled epidermis cells covering the mesophyll, which lies be- 

 tween two veins of the leaf ; 00, thick-walled epidermis cells covering in the vascular 

 bundles (,'/) ; j.^*, stomata leading to the spongy parenchyma, with large intercellular 

 spaces (i) ; in, mesophyll cells ; h, short hair on margin of leaf ; p, prosenchymatous 

 strand of cells strengthening the leaf margin. 



Vf&j as to derive the greatest possible benefit from the smallest 

 amount of substance. This is done by building the assimi- 



