These Box-tortoises become very tame. Although fond of drinking quantities of water in long and slowly repeated draughts, they do not go into the water, and if they fall in accidentally they are liable to get drowned. They enjoy a mixed diet, but animal food predominates, consisting chiefly of snails, the shells of which are passed, slugs, earthworms, maggots, and soft caterpillars. Their fondness for slugs is all the more remarkable since scarcely any other Vertebrate eats these slimy, sticky molluscs; but a Box-tortoise will make a meal of two or more fat specimens of the black slug Arion, and it will eat dozens of small slugs. It first deliberately smells the prey, turns the head sidewards and gives a bite, whereupon first the intestines and then the rest are eaten. The slime is later on scraped off with the fore-limbs, or the head is rubbed against the grass. The favourite time of feeding is towards dusk or in the early dewy morning, and they are especially lively during a soft, warm rain. They also relish various kinds of fungi and fruit, for instance half-rotten bananas. Close observation of their habits gives us indications as to how the change from carnivorous to herbivorous habits may have taken place. Accidentally many a blade of grass is bitten off and swallowed together with the molluscs, also bits of rotten wood and moss, and their excrements are often full of such more or less digested matter. They are not very fond of basking, although they love warmth, creeping into the grass, where they make a shallow form by moving the shell backwards and forwards. During the cooler nights they frequently retire into a hole or under a log of wood. They require to hibernate. If kept in a warm house they become restless in the autumn, refuse food, drink and feed again after some weeks, but are liable to die during the winter. If they can find a cool place they bury themselves and sleep for several months. If left out of doors they dig into the ground, creep into a hole, at the bottom of which they half bury themselves, or they hide under a heap of garden-rubbish well out of the reach of frost. Warm April days bring them out, and the first requirement is a drink.
When walking about in search of food they assume a curious attitude, with the shell well above the ground, the long neck stretched out and raised high. Their temper varies individually. Some become tame readily and lose all shyness, and creep up to their friend to take food from his fingers. Others are decidedly shy and sulky, withdrawing with a hiss into the shell, which in some specimens shuts almost hermetically all round, and they do not come out until all imaginary danger is past. One of my males sulked thus for several months, at least we never saw anything of it except the closed shell, but it did not starve itself. Propagation takes place in the summer, the long oval hard-shelled eggs being laid in June and July.
The typical Land-tortoises are easily recognised by their feet. The digits are short, have not more than two joints, and are without any trace of webs; the metacarpals are scarcely longer than broad. The hind-feet are club-footed. The skin on the anterior side of the fore-limbs is covered with strong horny scales, frequently with dermal ossifications. The plastron is united suturally by a broad bridge with the usually strongly arched carapace. The skull has complete postorbital and temporal arches. The top of the head is covered with shields. The tail is short. There are only a few recent genera, modifications of the central and typical genus Testudo. The latter is cosmopolitan in the warmer temperate and tropical regions, except in the Australian and Austro-Malayan countries.
Cinyxis (Fig. 82) with a few species in Tropical Africa from the Gambia and from Abyssinia to the Equator is remarkable for the unique modification of its carapace, the posterior portion of which is movable, the hinge passing between the seventh and eighth marginal and the fourth and fifth costal plates, externally behind the seventh marginal and the second costal shields. In the middle of the back the hinge is imperfect, the parts being merely flexible enough to permit the posterior half of the box to be closed. The head is covered with shields.
Fig. 81.–Skull of Testudo nigrita s. elephantopus, from the Galapagos Islands. × ½. M, maxillary; Op, Opisthotic; Pr.f, prefrontal; Pr.o, prootic; Pt.f, postfrontal; Q, quadrate; S.o, supra-occipital.
C. belliana, of Northern Tropical Africa, has a small nuchal shield, and the margin of the carapace is smooth. Length of shell up to seven or eight inches. C. homeana, of West Africa, has likewise a small nuchal shield, but the posterior portion of the carapace descends vertically, and the marginals are strongly reverted and serrated. C. erosa (Fig. 82), also from West Africa, has no nuchal shield; the marginals are reverted and serrated, but the posterior part of the carapace is sloping, and the anterior portion of the plastron is strongly forked in front, and projects beyond the anterior border of the carapace. This peculiar creature reaches a length of nine inches. When withdrawn within the shell, which is closed behind and depressed in front, with the jagged edges of the plastron and the anterior marginals protecting the drawn-in head, it has a very quaint appearance. It lives entirely on fruit and other vegetable matter, and is said to prefer to lie in the water, while C. belliana is supposed to be entirely terrestrial.
Fig. 82.–Cinyxis erosa. × ½.
Pyxis arachnoides, of Madagascar, a small land-tortoise, only four inches in length, has an immovable carapace, but the front lobe of the plastron is hinged.