Acting on this principle, foresters have arrived at a systematic method of treatment, under which large tracts of forest in Germany and France are now managed. The forests of a division, working circle, or district, are divided according to the description of the timber and the prevailing age of the trees, and it is the aim of the forester gradually to equalise the annual yield, and ensure its permanency. With this object, he divides the total number of years which are found necessary to enable a tree to reach maturity into a certain number of periods, and divides his forest into blocks corresponding with each period or state of growth. Thus, the beech having a rotation of 120 years, beech forests would be divided into six periods of 20 years each — that is to say, when the forest has been brought into proper order, there should be as nearly as possible equal areas under crop in each of the six periods, viz., from 1 year to 20, from 20 to 40, and so on. It is not necessary that the total extent in each period should be together, but it is advisable to group them as much as possible, and work each tract regularly in succession, having regard to the direction of the prevailing winds. When a block arrives in the last or oldest stage, felling is commenced by what is called a preparatory or seed clearing, which is very slight, and scarcely to. be distinguished from the ordinary thinning carried on in the former periods. This is followed by a clearing for light in the first year after seed has fallen (the beech seeds only every fourth or fifth year) with the objects of — 1st, preparing the ground to receive the seed; 2nd, allowing the seed to germinate as it falls; 3rd, affording sufficient light to the young seedlings. The finest trees are, as a rule, left standing, with the two-fold object of depositing the seed and sheltering the young trees as they come up. If there be a good seed year and sufficient rain, the ground should be thickly covered with seedlings within two or three years after the first clearing, Nature being assisted when necessary by hand sowing, transplanting from patches where the seedlings have come up very quickly, to the thinner spots, and other measures of forest craft. When the ground is pretty well covered the old trees are felled and carefully removed, so as to do as little damage as possible to the new crop, and the block recommences life, so to speak, nothing further being done until the first thinning. The above is briefly the whole process of natural reproduction, which is the simplest and most economical of all systems, and especially applicable to forests of deciduous trees. The period between the first or preparatory clearing and the final clearing varies from ten to thirty years, the more gradual and protracted method being now most in favour, particularly in the Black Forest, where the old trees are removed so gradually that there can scarcely be said to be any clearing at all, the new crop being well advanced before the last of the parent trees is removed. This approximates to "felling by selection," [Jardinage], which is the primitive system of working forests in all countries, under which, in its rude form, the forester proceeds without method, selecting such timber as suits him, irrespective of its relation to the forest increment. Reduced to system, it has certain advantages, especially in mountain forests, in which, if the steep slopes be laid bare area by area, avalanches, landslips, and disastrous torrents might result, but the annual output under this system is never more than two-thirds of that obtained by the rotation system, and there are other objections which it is unnecessary "to detail in this paper, which have caused it to be rightly condemned, and now-a-days only
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retained in the treatment of European forests under peculiar or special circumstances/