Page:The Oak.djvu/22

 supports. The stem or trunk is usually irregular when young, but becomes more symmetrical later, and after fifty years or so it normally consists of a nearly straight and cylindrical shaft with a broad base and spreading branches. The main branches come out at a wide angle, and spread irregularly, with a zigzag course, due to the short annual growths of the terminal shoots and the few axillary buds behind, and also to the fact that many of the axillary lateral buds develop more slowly than their parent shoot, and are cut off in the autumn. Another phenomenon which co-operates in producing the very irregular spreading habit of the branches is the almost total suppression of some of the closely-crowded buds; these may remain dormant for many years, and then, under changed circumstances, put forth accessory shoots. Such shoots are very commonly seen on the stems and main branches of large oaks to which an increased accession of light is given by the thinning out of surrounding trees.

The short ovoid buds develop into shoots so short that they are commonly referred to as tufts of leaves, though longer summer shoots often arise later. The latter are also called Lammas shoots. The crown of foliage is thus very dense, and the bright green of the leaves in early summer is very characteristic, especially in connection with the horizontal, zigzag spreading of the shoots.

While still young the tree is apt to keep its dead leaves on the branches through the winter, or at least