The cause of this difference is easily seen. When an artist had to represent an animal, his study of its form was not embarrassed by any such obstacle as a long and heavy robe. The animal could be watched in its naked simplicity and all its instinctive and characteristic movements grasped. The sculptor could follow each contour of his model; he could take account of the way in which the limbs were attached to the trunk; he saw the muscles swell beneath the skin, he saw them tighten with exertion and relax when at rest. He was not indifferent to such a sight; on the contrary, he eagerly drank in the instruction it afforded, and of all the works he produced those in which such knowledge is put into action are by far the most perfect; they show us better than anything else how great were his native gifts, and what a fund of sympathy with the beauties of life and with its inexhaustible variety his nature contained. Whether he model an animal separately or introduce it into some historic scene, it is always well rendered both in form and movement. This is to be most clearly seen in the rich and varied series of Assyrian reliefs, but the less numerous works of the same kind of Babylonian origin show the same tendency and at least equal talent. In copying the principal types of the animal world with fidelity and vigour, the Assyrian sculptors only followed the example set them by their south-country masters. [Illustration: FIG. 68.--Head of a cow, bronze. British Museum. Width across the cheeks 3¾ inches.] A cow’s head in bronze, which was brought from Bagdad by Mr. Rassam, is broad in treatment and of great truth (Fig. 68); the same good qualities are to be found in a terra-cotta tablet found by Sir Henry Rawlinson in the course of his excavations in the Birs-Nimroud (Fig. 69). It represents a man, semi-nude and beardless and with a stout stick in his hand, leading a large and powerfully made dog by a plaited strap. It is a sort of mastiff that might be used for hunting the wild beasts in the desert and marshes, the wild boar, hyena, and panther, if not the lion. The characteristics of the species are so well marked that naturalists have believed themselves able to recognise it as that of a dog which is still extant, not in Mesopotamia indeed, but in Central Asia.[167] We may seek in it for the portrait of one of those Indian hounds kept, in the time of Herodotus, by the Satrap of Babylon. His pack was so numerous that it took the revenues of four large villages to support it.[168] Similar subjects were represented upon other tablets of the same origin. One of them shows a lion about to devour a bull and disturbed by a man brandishing a mace. Nothing could be more faithful than the action of the animal; without letting go his prey he raises a paw, its claws opened and extended and ready to be buried in the side of the rash person who interrupts his meal.[169]