DESCRIPTIVE BOTANY. 



PART I. 



50 



"right-handed" (fig. 41. 6), or "left-handed" (a), 

 according as its coils appear to rise from left to 

 right, or from right to left, to a person supposed 

 to be placed in its axis ; or, if we were to hold the 

 spiral in an upright position before us, then the coils of 

 a right-handed spiral will seem to descend from the. 

 left towards the right, and those of a left-handed spiral 

 to descend from the right towards the left. 



(56'.) Knots, Internodia, and Joints. Many stems 

 are swollen at intervals, where the leaves are at- 

 tached, and such swellings are termed " knots." The 

 space which intervenes between two knots, is an " in- 

 ternodium." " Joints" are also swollen parts, where 

 the tissue is less firm than elsewhere (see art. 25.), and 

 may easily be fractured. They often occur immedi- 

 ately below the knots. 



(57.) Buds. As branches always originate in the 

 development of " buds," we shall here describe these 

 bodies, before we proceed with further details concerning 

 stems, of which the branches appear to form, as it were, 

 mere subdivisions. Buds usually consist 

 of several scales, or rudimentary leaves, 

 closely wrapped round an axis ; and 

 within these are other leaves, in a 

 still more rudimentary state, which 

 are destined to assume a more highly 

 developed condition than the outer 

 scales of the bud. It is the outermost 

 scales which thus serve to protect the 

 innermost and more delicate parts, from 

 the inclemencies of the weather. Some 

 are covered with down, which may, 

 as some suppose, be effective in pre- 

 serving them from the intensity of 

 cold ; others, as the horse-chestnut, 

 are coated over with gluten, which is 

 certainly a more effectual protection 

 against moisture ; and perhaps this is the end which 

 these scales best fulfil in most cases, as their closely im- 



