forest seems to be mainly clay; in spring or after heavy rains pools of water are formed, and these remain for a long time.

Between July 21 and August 27 a total of two hundred and eighty-five mouse traps set in the upland forest took on the first nights one short-tailed shrew and thirty northern white-footed mice. In addition to these species pine voles and a jumping mouse were trapped on days after the first. One shrew was caught alive August 30, as he was running about on the forest floor at 7:30 A.M. A few tracks of raccoon were seen from time to time on the road leading through the woods. A few fresh burrows of woodchucks were noted at the edges of benches and of ravines. A few red squirrels were seen at different times and two collected. Fox squirrels were rare, being noted only a few times; Mr. Norman A. Wood also saw these squirrels on two occasions in May. One cottontail was shot, in the climax forest. Mr. Wood collected a chipmunk in the climax forest on May 15, 1918, and saw another in the same habitat in May, 1919.

Aerial habitat:

Bats were seen on a few evenings, flying about over the climax forest, and over the adjacent region, but they were extremely rare, and efforts to shoot a specimen failed.

Modified and Artificial Habitats

Second-growth forest and scrub habitat:

Small trees and brush have grown up along the edges of many of the ravines in the cleared fields in and surrounding the preserve. Many of the trees are oaks, but beech and hard maple also occur, a few of them being relics from the original forest. Considerable brush is present, formed by a large variety of species. A few other small patches, especially in ravine bottoms and on flood-plains have been allowed to grow up to brush and small trees. In nearly every case these areas are heavily pastured.

The conditions here included in the second-growth forest and scrub habitat are not homogeneous, but differ in each different location where the habitat is found, tree and shrub species abundant in one situation not being present in another. The habitat is usually narrow in extent, being often confined to the width of the steep ravine wall.

Owing to its poor development and uncertain characteristics no intensive trapping was done in this type of habitat. A weasel was trapped in open beech-maple-oak forest at the edge of a cleared ravine, and a woodchuck was shot in the same type of habitat. Another woodchuck and a skunk were trapped at different times in low willow brush on the banks of the river just north of the woods. Northern white-footed mice, Pennsylvania voles, and a house mouse were trapped in thick oak brush and trees alongside a road north of the woods. A red squirrel was shot in second-growth oak and aspen woods in the north part of the preserve, and they were seen in open woods along ravines. Cottontails were noted a few times in blackberry thickets, in brush in ravines, in clearings along the river, and in beech-maple-oak forest along ravines.

Cleared-ravine sedge habitat:

A large ravine south of the river had been cleared of trees evidently several years previously, and it has now grown up mostly to sedges, grass, and iris in its more moist parts. Along the little brook which flows through the ravine there is a fringe of willows, and among the sedges a number of shrubs and small trees occur, mostly thorns and a few young sycamores and black walnuts.

Fifty mouse traps set in this habitat took on the first day, August 16, three northern white-footed mice and three Pennsylvania voles. More voles and a short-tailed shrew were taken on later days.

Cleared-upland rush habitat:

In the shallow, poorly drained depressions of the cleared upland the vegetation is dominated by rushes, which grow in clumps and form a thick growth, reaching a height of about one meter as a maximum. At the edges of the habitat and in places not thickly covered by the rushes a growth of sedges, grasses, and moss covers the ground; but under the thickest growth of rushes the ground is bare and is evidently covered by water during a part of the year. On this upland one small pond surrounded by rushes did not dry up until late in August. In a few places small blackberry thickets occur in the areas of rushes and dominate all other plants.

Fifty traps set in this habitat, on August 8, took on the first night one prairie white-footed mouse and one Pennsylvania vole; the prairie white-footed mouse was taken just at the edge of the growth of rushes. Other Pennsylvania voles as well as a lemming-vole, a prairie vole, and several young ground squirrels were secured on later nights by the same trap-line. A skunk den was situated in a blackberry thicket in the midst of the largest patch of rushes.

Cleared-upland sedge habitat:

Sedges are dominant over a part of the cleared upland, occurring on the moist gentle slopes which are too well drained for rushes, but not in any numbers on the drier and higher parts of the upland. With the sedges there are a few grasses, and the ground is sometimes covered by a moss, but the sedges are by far the most abundant plant.

Fifty mouse traps set in this habitat took on the first night, August 15, one prairie white-footed mouse and one prairie vole. Other prairie voles and white-footed mice were taken on later nights, as well as one Pennsylvania vole and one house mouse. Burrows of the thirteen-striped ground squirrel were numerous in the sedges.

Cleared-upland blue-grass habitat:

The most widespread habitat of the cleared upland on the south part of the preserve is the blue-grass habitat. In this habitat the blue-grass, Poa, is the dominant plant, growing to a height of usually not over 0.5 meter. With the blue-grass are