362 BRITISH FLOWERING PLANTS chap. 



said that the Spanisli Chestnut (Castanea sativa, 

 Fig. 250) also has alternate leaves in a plane parallel 

 to that of the branch, and with internodes of very 

 nearly the same length as the Beech. That is true ; 

 but, on the other hand, the terminal branches of the 

 Spanish Chestnut are stouter in proportion. Thus, 

 immediately below the sixth leaf, the Chestnut stalk 

 may be "15 of an inch in thickness, that of the Beech 

 not more than half as much. Consequently, the Chest- 

 nut could, of course, supposing the strength of the 

 wood to be equal, bear a greater weight of leaf; but, 

 the width of the leaf being determined by the distance 

 between the nodes, the leaf is, so to say, compelled to 

 draw itself out. Moreover, not only do the leaves on 

 a single twig thus admirably fit in with one another, 

 but they are also adapted to the ramification of the 

 twigs themselves. Fig. 249 shows a bough of Beech 

 seen from above, and it will be observed that the form 

 of the leaves is such that, while but little space is lost, 

 there is scarcely any overlapping. Each fits in perfectly 

 with the rest. 



The form of the Oak leaf is so familiar that it does 

 not strike us as anything peculiar, and comparatively 

 few of us, perhaps, have ever asked why it should be as it 

 is ; and yet it is peculiar, unlike that of any of our forest 

 trees, and those of the evergreen Oaks so abundant in 

 hotter countries. In botanical phraseology it is " decidu- 

 ous, oblong-oblanceolate, or oblong-elliptical, sinuated, 

 with blunt lobes extending not more than half-way 

 down to the midrib." The sinus between the lobes is 

 generally rounded off at the bottom. Again, though I 

 have not seen this mentioned in the botanical works 

 which I have consulted, they are rarely symmetrical, 

 the lobes of the two sides not corresponding. The three 

 points, then, which give the Oak leaf its peculiar form 

 are — 



1. The deep rounded sinuses. 



2. The want of symmetry of the two sides. 



3. The obovate or oblanceolate outline. 



