By this time a number of beavers were swimming in the pond after the manner of the first one. Presently all began to work. The addition already stood more than two feet above the water-line. The top of this was crescent-shaped and was about seven feet long and half as wide. It was made mostly of mud, which was plentifully reinforced with willow cuttings and aspen sticks. For a time all the workers busied themselves in carrying mud and roots from the bottom of the pond and placing these on the slowly rising addition. Eleven were working at one time. By and by three swam ashore, each in a different direction and each a few seconds apart. After a minute or two they returned from the shore, each carrying or trailing a long willow. These were dragged to the top of the addition, laid down, and trampled in the mud. Meantime the mud-carriers kept steadily at their work; again willows were brought, but this time four beavers went, and, as before, each was independent of the others. I did not see how this work could go on without some one bossing the thing, but I failed to detect any beaver acting as overseer. While there was general coöperation, each acted independently most of the time and sometimes was apparently oblivious of the others. These beavers simply worked, slowly, silently, and steadily; and they were still working away methodically and with dignified deliberation when darkness hid them. Beaver Pioneers I often wish that an old beaver neighbor of mine would write the story of his life. Most of the time for eighteen years his mud hut was among the lilies of Lily Lake, Estes Park, Colorado. He lived through many wilderness dangers, escaped the strategy of trappers, and survived the dangerous changes that come in with the home-builder. His life was long, stirring, and adventurous. If, in the first chapter of his life-story, he could record some of the strong, thrilling experiences which his ancestors must have related to him, his book would be all the better. "Flat-top," my beaver neighbor, was a pioneer and a colony-founder. It is probable that he was born in a beaver house on Wind River, and it is likely that he spent the first six years of his life along this crag and aspen bordered mountain stream. The first time I saw him he was leading an emigrant party out of this stream's steep-walled upper course. He and his party settled, or rather resettled, Lily Lake. Flat-top was the name I gave him because of his straight back. In most beaver the shoulders swell plumply above the back line after the outline of the grizzly bear. Along with this peculiarity, which enabled me to be certain of his presence, was another. This was his habit of gnawing trees off close to the earth when he felled them. The finding of an occasional low-cut stump assured me of his presence during the periods I failed to see him.