AUTUMNAL FOLIAGE 



strength. Moreover, it serves the leaf as veins 

 and arteries serve the human body, for sap creeps 

 through these woody tissues in slow but con- 



Leaf Venation 



tinuous circulation. All these leaf veins are 

 connected through the petiole or leaf-stem, with 

 long lines of cells and tubes in the tree body 

 leading up from the root and down again. 



Leaves are supplied with breathing-pores 

 called stomata, through which air and vapor 

 can pass freely. These are connected with 



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