io6 



CHES TNUT. YE W. 



[chap. 



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. 59 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 over-lapping. Each fits in perfectly with the 

 rest. 



Fig. 63. — Castanea. 



Fig. 64. — Caalanca and Beech. 



The leaves of the Yew (Fig. 65) belong to a type 

 very different from those which we have hitherto been 

 considermg. They are long, narrow, and arranged all 

 round the stem, but spread right and left, so that 

 they lie in one plane, parallel to the direction of the 

 branchlet, and their width bears just such a relation 

 to their distance apart that when so spread out their 

 edges almost touch. 



The leaves of Conifers are generally narrow and 

 needle-like. I would venture to suggest that this may 

 be connected with the greater uniformity in the struc- 

 ture of the wood as compared with that of Dicoty- 



