Last spring, in northern Pennsylvania I found myself on the top of a mountain, by the side of one of those trembling bogs locally known as bear-sloughs. There I had highly resolved to find the nest of a nearby Nashville warbler, which kept singing its song, which begins like a black-and-white warbler and ends like a chipping sparrow. I did not suppose that there was a bear within fifty miles of me. Suddenly I came upon a large, quaking-aspen tree set back in the woods by the side of the bog. Its smooth bark was furrowed by a score of deep scratches and ridges about five feet from the ground, while above them the tree had apparently been repeatedly chewed. I recognized it as a bear-tree. In the spring and well through the summer certain trees are selected by all the he-bears of a territory as a signpost whereon they carve messages for friend and foe. No male bear of any real bearhood would think of passing such a tree without cutting his initials wide, deep, and high, for all the world to see. The first flurries of snow mean bed-time for Bruin. He is not afraid of the cold, for he wears a coat of fur four inches thick over a waistcoat of fat of the same thickness. He has found, however, that rent is cheaper than board. Unless there comes some great acorn year, when the oak trees are covered with nuts, he goes to bed when the snow flies. One of the rarest adventures in wood-craft is the finding of a bear-hole where Bruin sleeps rolled up in a big, black ball until spring. It is always selected and concealed with the utmost care, for the blackbear takes no chances of being attacked in his sleep. The last bear-hole of which I have heard was not far from home. Two friends of mine were shooting in the Pocono Mountains with a dog, about the middle of November, 1914. Suddenly the dog started up a blackbear on a wooded slope. After running a short distance, the bear turned and popped into a hole under an overhanging bank. Almost immediately he started to come out again, growling savagely. I am sorry to say that my friends shot him. Then they explored the hole which he was preparing for his winter-quarters. It was beautifully constructed. The entrance was under an overhanging bank, shielded by bushes, and it seemed unbelievable that so large an animal could have forced his shoulders through so small a hole. The burrow was jug-shaped, spreading out inside and sloping up, while a dry shelf had been dug out in the bank. This was covered with layers of dry leaves and a big blanket of withered grass. In the top of the bank a tiny hole had been dug, which opened out in some thick bushes and was probably an air-hole. Just outside the entrance, a bear had piled an armful of dry sticks, evidently intending, when he had finally entered the hole, to pull them over the entrance and entirely hide it. The bear itself turned out to be a young one. A veteran would have died fighting before giving up the secret of his winter castle.