Testudo.–The plastron is immovable, except that in old individuals of some species, e.g. T. ibera, the hinder lobe develops a transverse flexible hinge. They have existed since the Oligocene of North America and Europe; and are now represented by nearly forty species in all the tropical and warmer temperate countries excepting the Austro-Malayan and Australian region. Typically terrestrial, herbivorous and frugivorous, although occasionally varying their diet with worms, molluscs, and insects. The eggs are hard-shelled, mostly less oval than those of the aquatic and semi-aquatic tortoises. The males generally remain smaller than the females, have a slightly longer tail, and have a concave instead of a flat plastron. Most land-tortoises hibernate in the ground during the cool and cold seasons, or they aestivate during the hot and dry months of tropical countries, but this is not an invariable rule.
T. graeca, the common "Greek Tortoise." The shell is very convex, without keels, and has a smooth, not serrated margin. The nuchal shield is narrow. The fifth or last neural shield is much broader than the others. The supracaudal is usually divided in the median line, so that this is really the last pair of marginals. The plastron is notched behind; the axillary and inguinal shields are small. The scales on the anterior surface of the fore-limbs are small, and form from half-a-dozen to ten longitudinal rows. The hinder surface of the thigh is quite smooth. The tip of the tail ends in a conical, horny spur. The coloration of the shell varies somewhat, but the ground-colour is yellow, each shield with a dark brown centre and irregular patches or confluent spots towards the margin. The plastron has an irregular, broad black border. The soft parts are grey-yellowish. Some specimens are rather pale, almost lemon yellow with little black; others incline towards orange with more or less black. The middle fields of the shields of young specimens are granular, although this area is rubbed smooth with age; but the rest shows clearly marked concentric lines of growth. The eyes are dark, with a brown or bluish tinge, sometimes inclining to dark grey in very old specimens.
Full-grown females have a shell six inches in length. This species inhabits the northern half of the Balkan Peninsula, parts of Asia Minor and Syria, Italy, and most of the islands of the Mediterranean, from the Grecian Archipelago to the Balearic Islands.
T. ibera is closely allied to T. graeca, from which it differs chiefly in the following points. The last pair of marginal shields are fused into an unpaired supracaudal, the median line of division being almost obliterated. The fifth neural shield is not broader, and generally a little narrower than the others. The posterior lobe of the plastron develops with age a transverse ligamentous hinge, and is thus rendered slightly movable, especially in the females. The posterior margin of the carapace is slightly expanded in old specimens. The scales of the fore-limb are large and imbricating, and form only four or five longitudinal rows. On the middle of the exposed posterior surface of the thighs the skin carries a strong, conical, horny tubercle. The coloration is much like that of T. graeca, except that the yellow of the young inclines to pale olive. Some specimens are uniform brownish. This species reaches a much larger size than T. graeca, old females often measuring eight inches, rarely more than nine inches in length. Its home is Morocco and Asia Minor, extending into Persia. It also occurs in certain parts of Southern Andalucia, where it breeds regularly, for instance, in the sandy pine-forests of the Marismas, near the mouth of the Guadalquivir. Whether it has been introduced from Morocco, or is indigenous, is an open question. Its specific name refers to its Iberian home.
T. marginata is worth mentioning, since it is the Greek tortoise, although not that of the European markets, which are supplied by the other two species. T. marginata is restricted to Greece proper, where it is the only land-tortoise. It is less closely allied to T. graeca than to T. ibera, of which it may be called an exaggerated form. The posterior margin of the carapace is much expanded or flanged, and serrated. The supracaudal is undivided, the posterior lobe of the plastron is movable, but the large conical spur on the thighs is absent. The dorsal shields of adult specimens are black with a small yellowish patch; the ventral shields are yellowish, each with a large black triangular patch. The British Museum possesses a shell 28 cm. = 11 inches in length.
The habits of these Moorish and Greek tortoises are very much alike, and since they enjoy the distinction of frequently being kept as pets in gardens, where they are allowed to look after themselves, a great many incidental and odd observations have been made on them. They are essentially vegetable feeders, but their taste varies individually and with the season, also according to the vegetation of the country they happen to come from. Most of them enjoy juicy plants, for instance, lettuce and cabbage; the flowers of the dandelion attract them not merely by their bright colour; clover is also a favourite food, and an enclosure of grass-land with clover in it is soon cleared of the latter; grass is also taken, in default of anything better. Some of my specimens gradually bite large holes into gourds and pumpkins; and in Morocco I found them in the autumn feeding entirely on the terribly astringent green fruits of the dwarf palm Chamaerops humilis. The larger specimens bolted the fruit with the stones, passing the latter. In close captivity they often learn to take and to like bread soaked in milk or water. They drink slowly and at length, but scarcely ever when they have succulent food. There is one thing which they do not eat, namely, "black beetles," although they are warranted to do so by the men who hawk them in the streets. Worms, slugs, etc. are often mentioned as part of their occasional diet, but I am not aware that any of the hundreds which I have watched have taken such creatures, in spite of every opportunity. Their habits are very regular. They learn to know the geography of their domain thoroughly, and the spot selected for sleeping will be resorted to over and over again, be it underneath some broad leaves, under a bushy fir-tree, between a cluster of wallflowers, or between some tussocks, or even in an almost bare corner, the attractions of which are not at all obvious. Although their mental capacities cannot possibly be called brilliant, they soon learn to distinguish between different persons, and they will come up to be fed; but their memory for localities is surprising. Here is only one instance. A tortoise which had been put into an outhouse for hibernation was six months later taken to its usual large enclosure, and in the afternoon it tucked itself away on the top of a mound under precisely the same low bush where it used to sleep during the previous autumn. It could not see that spot from where it had been put down, and it did not meander about during the day, but after having enjoyed the warm sun it made straight for its favourite place. Dr. Girtanner of St. Gallen in Switzerland testifies to their appreciation of music. When the town-band began to play on the square adjoining his garden, all his tortoises crept as fast as possible towards the fence and remained there motionless with heads and necks erect. When the piece was finished they moved about, but when the next number began they were again spellbound. This he has observed, not on one but on many occasions. That they can hear, although their ears are not visible, but covered by the ordinary skin, is obvious enough from the fact that during the pairing season they emit feeble piping sounds.
They are extremely fond of basking in the hot sun, sometimes allowing themselves to be almost baked in it, but then again at other times they seem to be anxious to seek the shade. They rise late and go to bed early, being absolutely diurnal. In the summer they leave their quarters when the sun is well up, making for a sunny spot to graze. Then they lie still and bask, unless a shower causes them to retreat under shelter. After some hours' rest they feed again, and in the afternoon, long before sunset, they go to bed. Some winters in England are of course much more severe than any which these tortoises experience in their native countries. Still they manage to survive them, provided they find a place which they can burrow into, deep enough to be out of the reach of frost; and if there is a heap of mould, rotting weeds, and leaves, they are probably safe. Sometimes they are restless, coming out again in unusually mild winters without, however, taking food. If they appear too early in the spring, they run the risk of terrible colds on prolonged wet and cold days, but in the autumn they are hardier, and can stand several degrees of dry frost.
The pairing season begins in May, but lasts far into the summer. In Morocco I found them pairing as late as the month of September. The preliminaries extend over many days. The male becomes unusually active, makes a piping sound, runs after the female, draws in its head, and knocks with its shell against that of the female. This is repeated many times, until the female is excited enough to raise itself upon its hind-limbs. The eggs, only two to four in number, are laid several weeks later, and are buried in the ground. They are roundish-oval, hard-shelled, and vary according to the size of the female. Those of T. graeca measure on the average 30 by 24 mm.; those of a large specimen of T. ibera 32 to 36 by 30 mm. The newly-hatched little creatures are still quite flexible, and apparently soon bury themselves before beginning their active life in the ensuing spring.
The age which these tortoises can reach is quite unknown, but there are reliable data of individuals having been kept for many years. Rumpf[[133]] kept two T. graeca in his garden at Frankfort-on-the-Main, and let them hibernate in a box with hay in the cellar. One lived 33, the other 23 years. The most famous specimen of T. ibera is "Gilbert White's Tortoise,"[[134]] which had been kept for more than 40 years before it came into his possession. It used to bury itself in November and to come out in April. It died in 1794, having reached an age of fifty-four plus an unknown number of years, since there is no record of its size when it came to England. The same applies to every other specimen which has been, and is being, observed as a pet. My largest Morocco female, which has a shell 7 inches long, shows at least 25 concentric rings of growth on the shields; the last half-dozen rings are very narrow, while some of those of the central area have been rubbed down. This creature is not improbably 30 years old. A small female, which is only 5¼ inches long, has already 14 rings on its still perfect shields. Lastly, a little one, only 4 inches long, shows 7 rings. They grow fastest when they are about 6 to 7 inches long, and they then seem to be at their prime. White's tortoise, now enshrined in the National Collection, was unusually large, the shell measuring 25 cm., or nearly 10 inches; around the much-enlarged, rubbed-down areola of each shield are about 30 very narrow rings.
T. horsfieldi is easily recognised by its possessing only four claws on the fore- and hind-limbs. It is closely allied to the species last mentioned, which it seems to represent in the sandy districts of Transcaspia and the Kirghiz Steppes to Afghanistan.