essential part of the monument of architecture to which it belongs, but while its origin cannot be definitely pointed out on Hellenic ground, it can be easily and positively traced in the Egyptian cave-architecture. Lepsius reverted to this question after his Egyptian journey, and in an academical treatise[37] he criticized sharply yet admiringly the fundamental conditions, the properties, and the merits of that Egyptian art, whose development he here, as elsewhere, followed with peculiar interest. He gave his attention also to the canon of proportions, that is, the binding rule according to which the Egyptian sculptors were obliged to measure and shape the relative proportions of the different parts of the human body. He had already been interested in the study of this subject in Rome, for in October, 1833, he saw a little bust in the Palin collection which was furnished on the under surface and both side surfaces with mathematically exact squares, the sides of which appeared to give him the unit of the canon. “The whole bust,” he tells Bunsen, “is wrought by this unit, which, in fact, according to my measurements of various statues, is contained about twenty-one times in the whole height.” This canon was well known to the Greeks, and Diodorus refers to it in the last chapter of his first book. According to him the body was to be divided into twenty-one and a quarter parts, and Lepsius now found that this rule conformed to the teachings of the later sculptors of the Ptolemaic era, who undoubtedly divided the human form up to the top of the forehead into twenty-one and one-quarter parts, but up to the crown of the head into twenty-three parts. Previous to this mode of division the canon had been twice altered, and both of these older rules (the more recent refers to the sculptures of the time of the pyramids), had for a fundamental unit the foot, which, taken six times, corresponded to the height of the body when erect, not indeed, as one would have expected, from the sole to the crown of the head, but only to the top of the forehead. The distinction between the first and second canon principally concerns the position of the knee: in the Ptolemaic canon, known to Diodorus, Lepsius found the general distribution itself changed. This he first discovered at Kom Ombos. We have always found the estimates of Lepsius entirely confirmed by our own measurements; yet, as the labors of Charles Blanc in the same department demonstrate, some other unit than the foot might be the basis of the canon of proportions, such as the finger in men, the claw in lions--_ex ungue leonem_.