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A STUDY OF LEAVES. 



VENATION. 



According to the distribution of the veins, 

 leaves are Net-veined or Parallel-veined — 



Net-veined, when the veins branch and cross 

 one another, forming an irregular network. 



Parallel-veined, when the veins run from the 

 base to the apex, or from the mid-vein to the mar- 

 gin, without branching. 



Parallel-veined. 



Net-veined. 



Nearly all the leaves of early spring flowers and 

 the grasses and herbs are parallel-veined, while 

 those of trees and woody shrubs are net-veined. 

 And yet many of the parallel-veined are evergreen, 

 enduring heroically the freezing winds of winter. 



