If all Chaldæan cylinders could be classed chronologically and by schools, epochs of perfection or of decadence would no doubt be observed, and also greater activity in some artistic centres than in others, the choice of subjects being modified from town to town and from age to age. In the present state of our knowledge we can only hazard conjectures with regard to this. M. Menant looks upon the cylinders which represent the goddess Istar holding her child upon her knees and receiving the homage of the faithful, as issuing from the workshops of Uruk (Erech); it is the prototype of the divine mother whose worship is to spread even into Greece. At Ur cylinders of very different types, but of a dry execution, which is rather a mark of decadence than of archaism, were manufactured: there are scenes of worship or initiation into mysteries, and sacrifices, among which that of the kid is the most frequent. On certain monuments M. Menant recognises a representation of human sacrifices: the most marked scene of this kind shows us a sacrificer, who, raising his right hand, brandishes a dagger over a kneeling child, whom he seems to prepare to slay, in the presence of a pontiff and of the statue of the god. One of the commonest figures on Chaldæan cylinders is that of the goddess Istar, sometimes decked with rich ornaments, sometimes entirely naked, in full face, with her hands clasping her breasts: this last type, profusely reproduced by the modellers in clay, was perpetuated all over the East up to the time of the Greek and Roman supremacies. CHAPTER II. _ASSYRIAN ARCHITECTURE._