n AMENTACE^ 369 



is three-fourths as long as its stipules. The leaf (Fig. 

 262) belonging to the fifteenth pair is longer and more 

 bulky than the stipule. The next leaf (Fig. 263) is 

 large, deeply concave, or rolled into a cylinder occupy- 

 ing the centre of the bud, and densely covered with 

 silky hairs on both surfaces, but particularly on the 

 back, as are all the others. 



The above description may be regarded as giving 

 the average composition of the winter or resting bud of 

 the Beech. Larger buds have a greater number of 

 leaves and stipules ; smaller buds, fewer. Strong shoots 

 on vigorous young trees have more leaves, though the 

 inner ones are small or but slightly developed in 

 winter. 



The buds gradually elongate. Before unfolding, 

 they turn slightly upwards, but afterwards bend down. 

 The long, narrow, pale-brown or straw-coloured stipules 

 are thrown off when the leaves expand, and sometimes 

 quite colour the ground under the tree. If the branch 

 is examined, the scars where the stipules were inserted 

 may be seen forming rings (Figs. 264) round the base 

 of each annual shoot. The shoot elongates consider- 

 ably between the leaves, but not between the leaf- 

 less stipules, so that the stipular rings remain close 

 together ; they are very persistent, and can be traced 

 for twenty-five years or more. 



The Beech is one of the most interesting cases of the 

 difference of structure of leaves in sunshine and in 

 shade. They have been carefully studied by Stahl.^ 

 The leaf consists of an upper epidermis, of one or more 

 layers of palisade cells, of a layer or layers of spongy 

 parenchyma, and a lower epidermis. Fig. 265 represents 

 a transverse section of a leaf grown in sunshine. There 

 are two layers of long palisade cells. Fig. 266 repre- 

 sents a similar section of a leaf grown in shade. There 

 is only one layer of palisade cells, which, moreover, are 

 broader and much shorter. The parenchyma is also 

 much reduced in thickness. The leaf is more delicate, 



' Jenaischer Zeitschr. f. Naturwiss. xvi. (1882-83). 



