The Sumerians did not attain the decorative effect of the Assyrian bas-reliefs with which the later kings lined the walls of their palaces. In fact, the small size of the figures rendered them suitable for the enrichment of stelæ, plaques, basins and stone vases, rather than for elaborate wall sculptures, for which in any case they had not the material. The largest fragment of an early bas-relief that has been recovered appears to have formed the angle of a stone pedestal, and is decorated with figures in several registers representing ceremonies of Sumerian worship.[26] In the upper register on the side that is best preserved is a priest leading worshippers into the presence of a god, while below is a crouching figure, probably that of a woman who plays on a great lyre or harp of eleven cords, furnished with two uprights and decorated with a horned head and the figure of a bull. On the side in the upper row is a heavily bearded figure on a larger scale than the rest, and the mixture of Sumerian and Semitic types in the figures preceding him suggests that the monument is to be assigned to the period of Semitic domination, under the rule of the kings of Kish or Akkad. But it is obviously Sumerian in character, resembling the work of Gudea's period rather than that of Narâm-Sin. [Illustration: Fig. 21.--Fragments of sculpture belonging to the best period of Sumerian art.--_Déc._, pl. 25, Figs. 4 and 6.] The perfection of detail which characterized the best work of the Sumerian sculptors is well illustrated by two fragments of reliefs, parts of which are drawn in outline in the accompanying blocks. The one on the left is from a bas-relief representing a line of humped cattle and horned sheep defiling past the spectator. It is badly broken, but enough is preserved to show the surprising fidelity with which the sculptor has reproduced the animal's form and attitude. Though the subject recalls the lines of domestic animals upon the Assyrian bas-reliefs, the Sumerian treatment is infinitely superior. The same high qualities of design and workmanship are visible in the little fragment on the right. Of the main sculpture only a human foot remains; but it is beautifully modelled. The decorative border below the foot represents the spouting vase with its two streams of water and two fish swimming against the stream. A plant rises from the vase between the streams, the symbol of vegetation nourished by the waters.[27] The extreme delicacy of the original shows to what degree of perfection Sumerian work attained during the best period.