20 



THE VEINS OF LEAVES. 



" Net-veined," when the veins branch and interlace in every 

 direction, a very common occurrence. (Fig. 41.) The large, 

 robust vein generally proceeding from the leaf-stalk to the 

 upper extremity, and di^'iding the lamina into two nearly equal 

 portions, is called the "midrib." (Figs. 31 and 40.) 



Fig. 41. ^'g- ^^■ 



Fig. 40 



Feather-veined," as in the hazle and Spanish chesnut. (Fig. 40.) 



Fan-veined," when like the ribs of a lady's fan, as in the syca- 

 more and Fig. 42. 



Ribbed," when there are three or five great longitudinal ribs, 

 as in rib-wort and the cinnamon-tree. (Fig. 43.) 



Parallel-veined," when numerous veins run side by side, without 

 any interlacing, and converge gradually to the point, as in the 

 lily of the valley. (Fig. 45.) 



Fig. 44. 



Fig. 4H. Fig- ^5. 



" Fork-veined," when like the letter V, with smaller v's proceeding 

 from the points. (Fig. 44.) This occurs only in ferns and a 

 Japanese tree called Salisburia. 



