FIG. 51.—TORTOISE (Testudo sulcata).
"In the family of land Tortoises (fig. 51), the feet are club-shaped, and their habits are terrestrial. The shell is very solid, thick, ovate, and (in the adult state) covered with horny concentrically-grooved shields, marked with a permanent areola. They have a short thick tail, are very slow in their motion, and live upon vegetables and roots. Most of the species are natives of the warm regions of the globe, but those that live in colder regions burrow and sleep during the winter. They are quiet, inoffensive animals, extremely tenacious of life, and remarkable for longevity. Individuals are stated upon good authority to have lived upwards of two hundred years.
"The common Tortoise, or Taragua (Testudo Græca), is a native of the south of Europe, and almost all the countries bordering on the Mediterranean; it is found in the islands of the Archipelago, Corsica, Sardinia, and in Africa, but is thought to be more common in Greece than elsewhere. It is from six to eight inches long, and weighs about forty-eight ounces. This species is often brought to this country and kept in gardens. One was brought to the Archiepiscopal garden at Lambeth, in the time of Laud, in 1633, where it lived till 1753, owing its death then, more to neglect than the effects of age."
BIRDS.
FIG. 52.—1, CONDOR (Sarcoramphus gryphus); 2, OSTRICH (Struthio camelus); 3, KIWI-KIWI (Apteryx).
The third class of the Vertebrata, comprises the "Birds," or those whose young are not born alive, but in the form of eggs; who have warm blood, and breathe by lungs, the air-cells of which communicate with the hollow shafts of the bones, (these are full of air instead of marrow), this gives them lightness, and serves as a reservoir of air while flying; they have two anterior extremities so modified as to form wings, and a heart with four cavities; most of them have the power of flying through the air, and some to a very great height, as the "Condor" (fig. 52), while in others the wings are rudimentary and only assist them in running, as in the Ostrich, (fig. 52) Cassowary, Penguin, &c., while in the "Apteryx" (fig. 52) they are quite absent.
Birds are covered with a peculiar modification of hair known as feathers; these consist of a central shaft with closely-set diverging branches, some of which have others branching from them with a serrated surface, giving them that peculiar metallic brilliancy so well shown in the feathers of the Humming Bird. Birds are furnished with beaks of almost every form, to suit their method of feeding, &c., and likewise feet, sometimes furnished with sharp and powerful talons, at others, feet suitable to climb with, and again in some they are webbed between the toes, so as to enable them to swim with great rapidity.
Birds are divided into five orders, as follows:—