THE LEAF. 



25 



nourishment. The former contains the nourishment in the 

 leaves ^base of leaves)^ and the two latter have it in the 

 thickened stem itself. 



24. The Bud. — At definite places on the stem occur 

 buds, which are simply undeveloped branches or shoots. 

 The scales of the buds are small leaves, and that on which 

 they are situated is the stem (as yet undeveloped). The 

 bud at the end of the stem is called the terminal bud 

 (Fig. 21, tef) ; the others are the lateral 

 buds. Of these, the majority occur in 

 the axils of the leaves (or if the leaves 

 have fallen, they may be seen just 

 above the leaf-scar), and for this reason 

 they are called axillary buds (Fig. 

 21, ax). Sometimes one or two are 

 produced on either side of or above 

 the axillary bud, and in such case 

 they are called accessory buds (Fig. 

 21, ad). Ocpasioually their place of 

 origin is indefinite or irregular ; they 

 are then called adventitious buds 

 (Fig. 21, ad). Many of the lateral 

 buds fail to develop into branches the following year, often 

 remaining dormant for severalyears; such are latent buds. 



THE LEAF. 



25. The Leaf is that organ of the plant which is 

 intended primarily for the presentation of a large amount 

 of surface expansion. Accordingly, we find it, as a rule, 

 very broad and long compared with its thickness. Ordi- 

 nary leaves, or foliage (Lat. folium, leaf), exhibit this 



Fig. 21. Buds : ier, terminal ; ax, axillary.; ac, accessory; ad, adventitious. 



