It is obvious that in every country native timber is preferred, provided it can be obtained in sufficient quantity at a cheap rate; if not, it is imported from other countries. In Britain, the first and most important of all trees is, of course, our own oak, of which we have two species and several varieties, belonging to the genus _Quercus_. The two species of oak natives of Britain, though greatly resembling each other in general appearance, may yet very readily be distinguished, when once their specific characters are pointed out. As these two species are very commonly confounded together, and as one of them is believed to afford a far more valuable timber than the other, it may be useful to note their difference, and exhibit the characters by which each may be known. The true British oak, _Quercus robur_, (fig. 1) bears its acorns on a stalk, or _peduncle_ (fig. 1, A), and hence it is sometimes called _Quecus pedunculata_, but its leaves grow close to the stem, without a footstalk, or at least with a very short one. In the other native species (fig. 2), these two characters are reversed: the leaves grow upon a footstalk, while the acorns are produced _sessile_, that is, sitting close to the stem (fig. 2, A); from which latter character this species has acquired the name of _Quercus sessiliflora_. [Illustration: Fig. 1. Fig. 2.] The above characters will, for the most part, be found pretty constant. At the same time, it may be remarked, that the oak is a tree subject to great variations; and accordingly individuals of each species occasionally occur, which in their characters are found more or less to approach those of the other. _Quercus robur_, for example, sometimes bears its acorns almost close to the stem, and sometimes _Quercus sessiliflora_ will bear them on a short footstalk. The leaves, too, of each, frequently vary in the length of the _petiole_, or leafstalk. But in a general way (as already stated), each kind may be readily distinguished by the above obvious points of difference. Both species are common in Britain, though _Quercus sessiliflora_ appears to be not so generally distributed as the other; in many districts its growth seems to be principally confined to woods and coppices, where it sometimes occurs even in greater abundance than the common species. _Quercus robur_ is believed to afford the more valuable timber of the two, owing, probably, to its being of slower growth. It is doubtful, however, whether the respective merits of each, in point of durability of timber, have yet been fairly put to the test. Where oak is grown in coppices, to be cut down periodically for poles, _Quercus sessiliflora_ is at least a valuable, perhaps a preferable tree, on account of its more rapid and cleaner growth.