But in course of time, as the people dwelling, when needful, in these secure retreats increased in numbers, and available caves became filled, the huts, especially in the more suitable shelters, were crowded together in each, until no longer built separately, but in irregularly continuous rows or groups at the rear, each divided from others by simple, generally straight, partitions, as are the dwelling divisions of the Tarahumári today. But unlike the latter, these hut-like rooms of the northern cave-dwellers were still rounded outwardly, that is, each hut (where not contiguous to or set in the midst of others, as was the case with those along the front), retained its circular form. The partitions and foundation walls were still built low, and still surmounted by converging cross-laid upper courses of logs or saplings and roofs of thatch. As with the Tarahumári, so with these earliest cliff dwellers of the north; their granaries were far more perfectly constructed than their own abiding places. To adequately protect their store or provision from seed-devouring animals, no less than from the elements, it became necessary to place it in dry crannies or pockets of the cliffs near at hand, preferably in recesses as far back in their caves as possible, and also to seal it up in these natural receptacles. At first (as may be seen in connection with the caves of Las Tusas, Arizona, containing some of the oldest and rudest separate hut remains I have yet examined) the mouths of these receptacles were walled up with dry-laid stones, carefully chinked, and plastered inside with mud, precisely as were the granary pockets of the Havasupai Indians seen by me in 1881. Later, while still the houses continued to be mere low-walled and partitioned sheds or huts of dry masonry, these granaries came to be quite well constructed, of mud-laid walls, and were enlarged, as stores increased with increase of settlement and tillage, until they had to be built outward from the niches like good sized, slightly tapering bins, protruding somewhat from the cave walls, and finally forming, as do the granaries of the Tarahumári today, miniature prototypes of the perfected single cliff house of a far later day.