The Western Prairie-“Dog,” or Prairie Marmot, (_Cynomys ludovicianus_).—Occupying a conspicuous hill-top near the Small-Deer House, and overlooking the Wild-Fowl Pond, is a circular enclosure, 80 feet in diameter, surrounded by an iron fence with an overhang, with walls going down to bedrock. This contains about fifty fat and jolly little Prairie Marmots, one-half of which are the gift of a Montana ranchman, Mr. Howard Eaton. The soil of the enclosure has never been disturbed, and there is no danger that the little creatures ever will be smothered in their burrows, as frequently happens in earth that has once been dug up and filled in again. Owing to its optimistic and even joyous disposition, the Prairie-“Dog” has many friends, and “happy as a Prairie-'Dog’” would be a far better comparison than “happy as a king.” His cousin, the woodchuck, has the air of being perpetually “in the dumps,” but the Prairie-“Dog”—never. His so-called bark is really a laugh, and his absurd little tail was given to him solely as a means of visible expression of good nature. But he has his enemies and detractors. The coyote loves his plump and toothsome body; the “granger” hates him for the multitude of his holes, and puts spoonfuls of poisoned wheat into his burrow. THE BEAR DENS, No. 37. The bears of the world form a very interesting group; and when its representatives are properly installed—in large, open yards, with abundant sunlight, fresh air and room for exercise—they develop finely, live happily, and furnish endless entertainment. Under proper conditions, bears are cheerful animals, full of the playful spirit that robs captivity of its chief terror. To confine large bears singly, in small cages, or in wet-floored, high-walled dungeons, or in the unspeakable “pits” of mediaeval type, is a sin against Nature. It is to be noted, however, that small and timid bears, like _Ursus japonicus_, are better off in small cages than in the very large ones; and it is for this reason that eight small dens have been provided, opposite the original series. The Zoological Society has put forth considerable effort in constructing a series of nine large Bear Dens which provide ideal conditions for their inmates. Bears do not need _buildings_! Their habits call for large, open yards, properly situated, with snug and dry sleeping-dens attached, to which they can retire whenever they wish. To them, masonry walls are worse than useless, for they cut off sunlight and promote dampness; but rocks and trees upon which to climb are very beneficial. In warm weather, all bears are fond of bathing, and a bathing pool in each cage is very necessary.