Other structural and kindred features of the cliff towns are found to be equally characteristic of the round ruins, features which, originating in the conditions of building and dwelling in the cliffs, came to be perpetuated in the round towns afterward built on the plains. So limited was the foothold afforded by the scant ledges or in the sheltered but shallow hollows of the cliffs where the ancient cliff dwellers were at first forced as a measure of safety to take refuge and finally to build, that they had to economize space to the utmost. Hence in part only the women and children, being smaller and more in need of protection than the men, were accommodated with dwelling places as such, the rooms of which were so diminutive that, to account for them, theories of the dwarfish size of the cliff dwellers as a race have been common. As a further measure of economy these rooms were built atop of one another, sometimes to the height of several stories--up, in fact, to the very roof at the rear of the cavern in most cases--and thence they were terraced toward the front in order that light and air might be admitted as directly as possible to each story. For the double purpose of accommodating the men and of serving as assembly rooms for councils and ceremonial functions, large circular chambers were constructed almost always out in front of the terraced dwelling cells of the women and children, and thus in the more exposed mouths of the caverns or shelters the villages nestled in. These round assembly rooms or kivas were often, indeed, built up from sloping portions of the sheer outer edge of the village cave shelf, in order to be as much as possible on a level with or even below the limited ground space between them and the houses farther back, so that the front along the lower and outermost row of these house cells might remain open and unobstructed to passage. The dwelling rooms or house cells themselves were made as nearly rectangular as was practicable, for only partitions divided them; but of necessity such as were placed far back toward or against the encircling and naturally curved rock walls, or the rear masonry walls, built in conformity to their curvature in all the deeper caves, had small triangular or keystone-shape spaces between their partitions. These, being too small for occupancy even by children, were used as storerooms for grain and other household supplies. When the cave in which a village was built happened to be very deep, the living rooms could not be carried too far back, as neither light nor sufficient air could reach them there; hence here, chiefly against the rear wall or the cave back itself, were built other storerooms more or less trapezoidal in shape, according to the degree of curvature in the rock face against which they were built, or, as said before, of the rear wall itself, which in the deeper caves often reached from floor to roof and ran parallel to the natural semicircular back of the cavern.