_Paper birch--aspen stage:_ The continued growth of the young trees in the shrub stage leads to the production of a sapling forest of the more quickly growing species, the paper birches and aspens. Often one or other of these species becomes dominant to the practical exclusion of the other, but sometimes both occur together. On the slopes near the lakes of the Cisco Lake chain aspens are rare, and the sapling forests on the clearings and burns are almost a pure stand of paper birch. Near Watersmeet, however, the aspen seems to be the dominant form, and few paper birches were seen. Near Gogebic Lake, also, the quaking aspen is the dominant form, though paper birches are common in the sapling forests. The growth in these sapling forests is very thick, and the ground is nearly bare of vegetation, though it is heavily covered with dead sticks and small logs. In a thick growth of quaking aspens, on wet ground studied near Gogebic Lake, a number of alders and paper birches, a few young trees of sugar maple and arbor-vitae, and a rare elm occur. A scanty undergrowth of mountain maple and numerous sugar maple seedlings is present. Few mammals are found in this stage of the forest. On the western slope of Birch Point on Cisco Lake there is a good stand of paper birches, growing in an open stand with much grass in the spaces between the trees. This place has been much used for camping and it may be that the development of the grass is the result of opening the forest by clearing out some of the trees. Among the birches are numerous young firs and white pines, with a few young sugar maples, and a rare arbor-vitae. The birches show many signs of age, and would evidently, if undisturbed, soon give way to a forest dominated by the pines and firs. In the grass among these trees deer-mice, red-backed voles, and jumping mice (Zapus) were taken. Signs of snowshoe hare were seen. _Young hardwood forest stage:_ On the eastern slope of a low ridge at Birch Point, Cisco Lake, a young hardwood forest is rapidly replacing a former growth of paper birches which has followed a fire. In this growth numerous old paper birches still persist, but they are being strongly crowded by a thick growth of vigorous young sugar maples, some of which have trunk diameters up to about eight inches, and which form a dense shade. Among the maples are numerous young firs and a few young hemlocks and arbor-vitae. The ground is mostly bare, being scantily covered by leaves. The soil is moist, but there is no grass and little brush. In this habitat deer-mice were taken, and one red squirrel was seen. _Artificial Conditions_