Page:EB1911 - Volume 19.djvu/971

 is generally very hard and durable. The oak will not bear exposure to the full force of the sea gale, though in ravines and on sheltered slopes oak woods sometimes extend nearly to the shore. The cultivation of this tree in Europe forms one of the most important branches of the forester’s art. It is frequently raised at once by sowing the acorns on the ground where the trees are required, the fruit being gathered in the autumn as soon as shed, and perfectly ripe seeds selected; but the risk of destruction by mice and other vermin is so great that transplanting from a nursery-bed is in most cases to be preferred.

The growth of the oak is slow, though it varies greatly in different trees; Loudon states that an oak, raised from the acorn in a garden at Sheffield Place, Sussex, became in seventy years 12 ft. in circumference; but the increase of the trunk is usually very much slower, and when grown for large timber oak can rarely be profitably felled till the first century of its growth is completed. The tree will continue to form wood for 150 or 200 years before showing any symptoms of decay. As firewood oak holds a high position, though in Germany it is considered inferior to beech for that purpose. It makes excellent charcoal, especially for metallurgic processes; the Sussex iron, formerly regarded as the best produced in Britain, was smelted with oak charcoal from the great woods of the adjacent Weald, until they became so thinned that the precious fuel was no longer obtainable.

The British oak grows well in the northern and middle states of America; and, from the superiority of the wood to that of Q. alba and its more abundant production of acorns, it will probably be much planted as the natural forests are destroyed. The young trees require protection from storms and late frosts even more than in England; the red pine of the north-eastern states, Pinus resinosa, answers well as a nurse, but the pitch pine and other species may be employed. In the southern parts of Australia and in New Zealand the tree seems to flourish as well as in its native home.

The oak in Europe is liable to injury from a great variety of insect enemies: the young wood is attacked by the larvae of the small stag-beetle and several other Coleoptera, and those of the wood-leopard moth, goat moth and other Lepidoptera feed upon it occasionally; the foliage is devoured by innumerable larvae; indeed, it has been stated that half the plant-eating insects of England prey more or less upon the oak, and in some seasons it is difficult to find a leaf perfectly free from their depredations. The young shoots are chosen by many species of Cynipidae and their allies as a receptacle for their eggs, giving rise to a variety of gall-like excrescences, from which few oak trees are quite free.

In North America, where the species of oak are very numerous, the most important member of the group is Q. alba, the white oak, abounding all over the eastern districts of the continent from Lake Winnipeg and the St Lawrence countries to the shores of the Mexican Gulf. In aspect it more nearly resembles Q. Robur than any other species, forming a thick trunk with spreading base and, when growing in glades or other open places, huge spreading boughs, less twisted and gnarled than those of