Ptarmigan in summer. Davison, Zoology. are best known to us are the hawks, the condor, with its great sweep of ten feet from wing to wing, and the eagle. To the hawks belong two birds which are, because of their habits, harmful to man. They are the sharp-shinned hawk and Cooper's hawk. IV. WADERS.-These are birds with unusually long legs and long necks, the latter character being a natural correlation of greatest service in food getting. Examples are the mud hen or coot, the snipe, crane, heron, and stork. The last two are the giants of the group. THE SWIMMERS AND DIVERS. Birds placed in these orders have snow which surrounds it; in the spring it molts, turning to a gray and white, thus resembling the lichens among which it feeds. III. BIRDS OF PREY.These birds are characterized by the strong hooked beak, adapted to tearing, and by the sharp claws, which are curved and strong. The need of a gizzard, which is a prominent part of the digestive tract in a grain-eating bird, has here almost completely disappeared, the crop serving to macerate the food. show this use of the muscular gullet and crop, for the hair and skeletons of the mice which form their prey are ejected in a small ball, by means of the gullet organ. Members of this group that Owls Golden eagle (Aquila chrysaetos). North America and Europe. Copyright, 1901, by N.Y. Zoological Society. Sandbill crane, showing habitat. From mounted group at the American Museum of Natural History. the feet webbed, the wings are often adapted for long and swift flight. In this division are placed the gulls, terns, ducks, geese, loons, auks, and puffins. OTHER ORDERS. -Other orders of birds which we are likely to see and recognize may be mentioned. They include the doves, the only remaining native representative being the mourning dove; the woodpeckers, strong and long of bill, the friend of the lumberman as a savior of the trees from boring pests which live under the bark; the swifts and humming birds, the latter among the tiniest of all vertebrate animals; and the parrots, of which we have only one native form, the Carolina paroquet (Conurus carolinensis). This bird once had a range north as far as the Great Lakes; now it is found only in South America. RELATIONSHIP OF BIRDS AND REPTILES. -The birds afford an interesting example of how the history of past ages of the earth has given us a clew to the structural relation which birds bear to other animals. Several years HUNTER'S BIOL. - 20 ago, two fossil skeletons were found in Europe of a birdlike creature which had wings and feathers, but also teeth and a lizardlike tail. From these fossil remains and certain structures (as scales) and habits (as the egg Common tern (Sterna hirundo) and young, showing nesting and feeding habits. laying habits), scientists have concluded that birds and reptiles in distant times were nearly related and that our existing birds probably developed from a reptilelike ancestor millions of years ago. CLASSIFICATION OF BIRDS DIVISION I. Ratitæ. Running birds with no keeled breastbone. ostrich, cassowary. DIVISION II. Carinatæ. Birds with keeled breastbone. Examples, ORDER 1. Passeres. Perching birds; three toes in front, one behind. One half of the birds are included in this order. Examples, sparrow, thrush, swallow. ORDER II. Gallina. Strong legs; feet adapted to perching. Beak stout. Examples, jungle fowl, grouse, quail, domestic fowl. ORDER III. Raptores. Birds of prey. Hooked beak. ples, eagle, hawk, owl. ORDER IV. Grallatores. Strong claws. Exam Waders. Long neck, beak, and legs. Examples, snipe, crane, heron. ORDER V. Natatores. Divers and swimmers. Legs short, toes webbed. Examples, gull, duck, albatross. ORDER VI. Columbæ. pigeon. ORDER VII. Picaria. Like Gallinæ but with weaker legs. Examples, dove, Woodpeckers. Two toes point forward, two back ward, and adaptation for climbing. Long, strong bill. REFERENCE BOOKS FOR THE PUPIL Herrick, Text-book in General Zoology, Chaps. XXII, XXIII. American Book Company. Beebe, The Bird. Henry Holt and Company. Nature Study Leaflets, XXII, XXIII, XXIV, XXV. N.Y. Department of Agriculture. FOR THE TEACHER Apgar, Birds of the United States. American Book Company. Beebe, The Bird. Henry Holt and Company. Bulletins of U.S. Department of Agriculture, Division of Biological Survey, Nos. 1, 6, 15, 17. See also Year Book, 1899. Chapman, Bird Life. D. Appleton and Company. Riverside Natural History, Vol. IV. Houghton, Mifflin, and Company. The Rabbit. XXVI. MAMMALS Living rabbits may be kept in the schoolroom in a box open at one end, the open end protected by a door covered with wire screening. A rabbit thus kept, if given a little care, soon becomes accustomed to his surroundings and will prove a very acceptable addition to the laboratory. Adaptations to Its Life. The rabbit in a wild state makes its home under clumps of dried grass, brush, and the like. Its English cousins make burrows in the ground. The rabbit escapes observation from its enemies by means of its color, which often closely resembles that of the thickets in which it hides. Notice the body covering; is it uniform in color and thickness? The hair forms a protection from the cold. In summer the color of the coat is more earthlike than in the winter. Some arctic forms undergo a complete change of coat from gray in summer to white in the winter. Compare the fore limbs of the rabWood hare. From photograph loaned by bit with your own arms; do you find the American Museum of Natural History. upper arm, forearm, wrist, and hand? In the same manner find the parts corresponding to thigh, shank, and foot in your own leg. Notice the different methods of locomotion in the rabbit; seek the ways in which the limbs of the rabbit are adapted to the function of locomotion. Notice the feet to see if they are adapted for digging or for any other purpose. The rabbit relies principally on swiftness and agility in flight rather than in ability to cope with an enemy with teeth and claws. Frequently they will remain in absolute quiet, allowing their arch-enemy, the dog, to pass close to them, relying on their protective coloration to escape notice. When chased by the dog, they have the instinct of running in a circle and will during the chase suddenly jump to one side at a sharp angle in order to throw the dog off the scent. The teeth are of considerable importance in connection with the food and the method of obtaining food. Notice the prominent cutting teeth (the incisors). Note the cleft upper lip. Feed a carrot to the rabbit and determine the use of the cleft. Which jaws move during feeding? Notice that they move sidewise as well as vertically; this horizontal movement is of considerable use in grinding the food. If you examine the prepared skull of a rabbit the different kinds of teeth may be easily identified and their functions learned. In front are found the incisors. How many in each jaw? Separated from the incisors by a gap are the molars or grinding teeth. How are such teeth adapted to their function? With a hand glass note the position of.the |