Beavers coöperate and carry out a distinct plan; in doing this they work both unitedly and singly. The whole work, however, advances as though to a plan and as though under constant supervision. Through the years I have seen beavers working hundreds of times. Their work is nearly always efficient and apparently under the direction of an expert in beaver work; but never have I seen any sign or signal given by a beaver that I could positively say was an order or command. But I see no way of explaining the magnitude of beaver works and the skill shown therein except through coöperation under an acknowledged leader. One evening as I was watching, a bobcat chased two beavers into the pond. A few yards farther and they would have been overtaken. But the instant they dived into the pond they were safe. The wild enemies of beavers are lions, bears, wolves, and wildcats; in fact, any flesh-eating animal large enough to kill one. Rarely is a beaver captured in water; he is a swift swimmer and can long remain under water. But on land he is slow getting into action, is not agile, and in going has only low gear. For safety he aims to cut trees that are closest to the water. Another evening four, and a part of the time five, beavers were pushing and dragging a log. When they at last pushed it into the canal one beaver with only one forepaw put this forepaw against the end of the log and conducted it down the canal. For safety for travel, and for transportation beavers need deep water. There is a social side, too, to life in these deep-water homes. Not only do beavers indulge in all kinds of water sports among themselves, but they seem to make friends with some of their diving, swimming neighbours in other animal families. I had often heard that beavers ever war upon their little brother, the muskrat. The beavers in this colony did not. They continued to use the old repaired house until near the close of their harvesting. On their departure, apparently muskrats at once took possession. But the beavers often went back into the old house. One day I saw a beaver enter the house. There were a number of muskrats inside. I do not know the nature of his visit but there was no excitement. Another time a beaver turned aside and touched noses with a muskrat. Still another time a beaver playfully dived beneath a muskrat. As the beaver came up the muskrat grabbed beaver fur with forepaws and sat down on the beaver’s back. Away swam the beaver with back above the water, little brother holding on. The harvest of aspens for winter food was nearly finished, and I had thus far seen only the old beaver doing any tree cutting. The evening of the 19th of October I had gone through the aspen groves measuring and counting. One hundred and twelve aspens had been cut; these were from two to eleven inches in diameter at the place of cutting, and from five to nineteen inches above the ground. The aspens were from twelve to twenty-one feet high.