LEAVES. 



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sioncd by the origin of the primary veins. If the veins take 

 their rise along the midrib and proceed to the margin, giving 

 the leaf, in structure, a resemblance to a featlier, it is called 

 the Feather veined, as seen in fig. 37, which represents the 

 leaf of the Chestnut. The form of tlie leaves 

 oiy of this variety, depends on the direction and 

 relative length of the veins. If, as in the chest- 

 nut, the veins make an acute anjrle with the 

 midrib, and proceed straight forward to the 

 margin, the leaf is proportionally lengthened, 

 and takes the name of laneeohite. If the mid- 

 rib and veins near the apex are considerably 

 elongated its apex is said to be aetiminatc. If 

 the primary veins are short and of nearly equal 

 length, the leaf will be narrow and elongated, 

 and is denominated ltneak. (fig. 38.) If the 

 veins that proceed from the middle of tlie mid- 

 rib arc larger than (hose of the ai)ex or base, it assumes the 

 the form of fig. 39, a, or 

 some similar outline, 

 and form the varieties 

 oblong, oval, eliptic, 

 or in some cases ap- 

 proaching orbicular (fig 

 39, b.) If the veins 

 springing from the base 

 are larger than tlie rest, 

 and proceed from the midrib at 

 a greater angle, the leaf assumes 

 the oral form, (fig. 40,) but if the 

 reverse takes i)lace with the veins, that is, if the veins above 

 the middle be the longest, the shape of the leaf will 

 10 be reversed and wq shall have the obovatc leaf, 

 (fig. 41.) It not un frequently hap- 

 pens, that the veins that originate at 

 the base of the midrib are nearly as 

 large as the midrib itself, and run 

 in nearly a parallel direction with 

 it, as in the Cornus, (fig 42.) — 

 These arc called ribbed leaves, and 

 the student must be careful not to 

 confound this variety with parallel 

 veined leaves from which he may in most cases, ca- 



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