Page:The Oak.djvu/21

 structure and life-processes of the tree, we may turn to the investigation of its cultivation and the diseases which attack it, concluding with a necessarily brief chapter on the systematic position of the British oak and its immediate allies, and some remarks on its geographical distribution at the present time. Of course, many points which will turn up in the course of the exposition will have to be shortly dealt with, as the object of the book is to touch things with a light hand; but it is hoped that, this notwithstanding, the reader may obtain a useful glimpse into the domain of modern botanical science and the problems with which forest botany is concerned, and with which every properly trained forester ought to be thoroughly acquainted. The oak, as is well known, is a slow-growing, dicotyledonous tree of peculiar spreading habit, and very intolerant of shade (Plate I). It may reach a great age—certainly a thousand years—and still remain sound and capable of putting forth leafy shoots.

The root-system consists normally of a deep principal or tap root and spreading lateral roots, which become very thick and woody and retain a remarkably strong hold on the soil when the latter is a suitable deep, tenacious loam with rocks in it. They are intolerant of anything like stagnant water, however, and will succeed better in sandy loam and more open soils than in richer ones improperly drained.

The shoot-system consists of the stem and all that it