FOLIAGE-LEAVES. 



115 



narrower than the base, and those in which the apex is 

 broader than the base. 



172. In the first of these three classes it is evident that 

 any variation in the outline will depend altogether on the 



Fig. 152. 



Fig. 153. Fig. 149. Fig. IBO. 



Fig. 161. 



i^elation between the length and the breadth of the leaf. 

 fWhen the leaf is extremely narrow in comparison with its 

 length, as in the Pine, it is acicular or 

 needle-shaped (Fig. 145). As the width 

 increases, we pass -through the forms 

 known as linear, oblong, oval, and 

 finally orbicular, in which the width 

 and length are nearly or quite equal 

 (Fig. 146). 



Fig. 1B4. 



173. In the second class the dififerent 

 forms arise from the varying width of 

 the base of the leaf, and we thus have subulate or awl- 

 shaped (Fig. 147), lanceolate, ovate, and deltoid leaves 



(Fig. 148). : 



Figs. 149 to 154. — Various forms of foliage -leaves. 



