The Rocking Stone stands on a smooth table of granite on the southern shoulder of the hill overlooking the Buffalo Range. Its extreme height is 7 feet 6 inches; breadth, 10 feet 1 inch; thickness, 8 feet 1 inch, and its weight, as roughly calculated, is 30 tons. A pressure of about 50 lbs. exerted on the most northern angle of the stone causes its apex to swing north and south about two inches. [Illustration: WHITE TAILED DEER.] SECTION I.—THE MAMMALS. The Hoofed Animals. The forming of a collection which shall fairly represent the hoofed animals of the world is necessarily a work of years. It is now (in 1915) fifteen years since the Zoological Society entered upon this task, and during that period the work of providing installations and living specimens has been pursued with unflagging industry. In no feature of our development has the Society been more liberal than in the purchase of specimens for this collection, and the gifts to it have been both numerous and valuable. In our 82 species and 330 specimens we feel that the Order _Ungulata_ is strongly represented. On April 1, 1913, the summary of groups stood as follows: Summary of the Ungulates. Deer 24 species 164 specimens Giraffes 1 “ 2 “ Bovines: Bison, etc. 3 “ 38 “ Musk Ox 1 “ 6 “ Wild Sheep, Goats, etc. 8 “ 41 “ Antelopes 22 “ 41 “ Hippopotamus 2 “ 4 “ Wild Swine 3 “ 5 “ Camels and Cameloids 5 “ 10 “ Rhinoceros 2 “ 2 “ Tapirs 2 “ 3 “ Wild Equines 6 “ 9 “ Elephants 3 “ 5 “ Total 82 “ 330 “ The arrangement of this section of the Guide Book begins at the Buffalo Entrance with the Bisons, and follows the ranges, corrals and buildings for Hoofed Animals, along the southern and western sides of the Park, to the Axis Deer Range. The Elephant House is introduced as the visitor leaves Baird Court, going south. The large, open pastures are called “ranges,” and the smaller fenced enclosures are known as “corrals.” The fences are chiefly of hard steel wire, so strong and elastic that the animals cannot break through them. [Illustration: AMERICAN BISON: BULL.]