There is, perhaps, no soil so bad and barren that it may not be rendered either profitable or ornamental by judicious planting; but, as might be expected, there is often a great want of knowledge as to the proper kind of trees to be chosen to suit a particular soil. In looking over a large extent of woodland one will often be struck with the great disproportion in size of the individual trees of a species; but it will generally be noticed that where the largest and healthiest occur the tree is usually growing upon its own soil, and is found to be flourishing at the expense of all around it. Thus the finest oaks will be found where the soil is deep and loamy, resting on clay; beech, and the Austrian pine (_Pinus austriaca_) upon a calcareous gravel, resting on a bed of chalk; ash and elm on a dampish, loamy gravel; birch in a light, black loam, with a gravelly substratum; Spanish chestnut, in a good loamy or gravelly soil, not too damp; the Scotch and Corsican pines (_P. sylvestris_ and _P. laricio_) at fairly high altitudes, and in gravelly, well-drained soils; and the Cluster and Aleppo pines (_P. Pinaster_ and _P. halepensis_), in almost pure sand on the sea-coast. Some trees grow rapidly for a few years in almost any soil, but where the soil is unsuitable they generally show signs of distress after a time, make little or no progress, and ultimately become stunted and ill-grown. Should the soil be very unfavourable, they die outright. Instances of this are, unfortunately, far too common wherever one travels over the country, owing to trees of a kind that are utterly unfitted for the particular class of soil being planted in a haphazard kind of way, without any consideration of their individual requirements. For all practical purposes with reference to tree-culture, soils, generally speaking, may be divided into six distinct classes—peaty, chalky or limey, gravelly, clayey, loamy, and such as contain ironstone, coal, etc.