98 THE STEM. 



their position, but from their gradual transition into ordinary leaves 

 in many cases. This is well seen in the expanding buds of the 

 Lilac, Hickory, Horsechestnut, and especially of the Buckeye. 

 The scales represent, sometimes the blade of the leaf, as in the 

 Lilac ; but more commonly the dilated base of the leaf-stalk, 

 as is evident in the Balsam Poplar, Butternut, and Hickory ; or 

 their stipules (259), either combined with this base, as in the Mag- 

 nolia (Fig. 131), or alone, as in the Tulip-tree. Scales passing 

 into ordinary leaves are abundantly obvious on the turions, or 

 subterranean budding shoots, of numerous perennial herbs. 



147. By the development of the preexisting bud in the embryo, 

 the original stem is produced ; and it may be continued from year 

 to year by the continued evolution of a terminal bud. Growing in 

 this way only, the stem would of course remain simple or un- 

 branched ; as is the case with many during the first year, and with 

 others, such as most Palms (Fig. 166) and Reeds throughout their 

 whole existence. But more commonly branches appear, even 

 during the first year's growth. 



SECT. II. RAMIFICATION. 



148. Branches spring from lateral or axillary buds. These are 

 new undeveloped axes or growing points, which habitually appear, 

 or at least may appear, one (or occasionally two or three) in the 

 axil of each leaf, that is, in the upper angle which the leaf form.s 

 with the stem. (See Fig. 127, c, where the point at which the 

 fallen leaves were attached is marked by the broad scar, Z>, just be- 

 low the bud.) The axillary bud is at first a little cellular nucleus 

 on the surface of the wood, at the end of one of the cellular lines 

 that form the silver-grain (196), and underneath the bark, through 

 which it pushes as it grows, and shapes itself into a rudimen- 

 tary axis, covered with the little appendages which become scales 

 or leaves. When these buds grow, they give rise to BRANCHES ; 

 which are repetitions, as it were, of the main stem, growing just 

 as that did from the seed ; excepting merely, that, while that was 

 implanted in the ground, these proceed from the parent stem. 

 The branches thus produced are in turn provided with similar 

 buds in the axils of their leaves, which have the same relation to 

 the primary branch that it has to the main stem, and are capable 

 of developing into branches of a third order, and so on indefinite- 



