84 THE PLANT: A GENERAL INTERNAL VIEW 



Through them the water, and 

 the particles of other substances 

 in it, reach at last the soft green 

 cells of the leaves. (See Figure 

 J5-) This is the end of the jour- 

 ney we have followed. Here the 

 chloroplasts, food makers for the 

 world, are busy while daylight 

 lasts in the work of photosyn- 

 thesis. Here inorganic substances 

 are to become organic. Particles 

 are to be rearranged and joined 

 with other particles. Here, in the 

 new food particles, is to be stored 

 the force which sustains life, the 

 energy on which all living sub- 



Fig. 34. — Part of the leaf skele- 

 ton of a rubber plant. The soft 

 parts of the leaf have been re- 

 moved. The smallest veins of 

 all do not show in the picture. 

 — PhQto. by Land. 



stance feeds and from which it is renewed. 



26. Inside the Leaf. — Here are dim, green spaces be 

 tween loose, thin-walled cells. The light filters through 

 The tissue under 

 the epidermis is 

 called the meso- 

 phyll. (M eso 

 means in the 

 midst of ; phyll 

 means leaf.) 

 Under the upper 

 epidermis a layer 

 of the mesophyll 

 forms what is called the palisade tissue. (See Figure 36.) 

 The cells of the palisade stand closely side by side, like logs 



Fig. 35. — The ending of one of the smallest veins in 

 the mesophyll ; /, a water-conducting vessel ; i, an 

 intercellular space. 



