The ruins in the Gila valley, including those along Salt river, are less known than those farther northward, but we know that there is a marked difference between the type exemplified by the well-known Casa Grande, near Florence, Arizona, and that of which the best specimens (notably the Chaco ruins) are found in the San Juan basin. This difference may be due only to a different environment, necessitating a change in material employed and consequent on this a change in methods, although it seems to the writer that the difference is perhaps too great to be accounted for in this way. Be the cause what it may, there is no doubt that there is a difference; and it is reasonable to expect that in the regions lying between the southern earth-constructed and the northern stone structures, intermediate types might be found which would connect them. The valley of Rio Verde occupies such an intermediate position geographically, but the architectural remains found in it belong to the northern type; so we must look elsewhere for connecting links. The most important ruin in the lower Verde region occurs near its southern end, and more distinctly resembles the northern ruins than the ruins in the northern part of that region. Although the examination of this region failed to connect the northern and southern types of house structure, the peculiar conditions here are exceptionally valuable to the study of the principles and methods of pueblo building. Here remains of large villages with elaborate and complex ground plan, indicating a long period of occupancy, are found, and within a short distance there are ruins of small villages with very simple ground plan, both produced under the same environment; and comparative study of the two may indicate some of the principles which govern the growth of villages and whose result can be seen in the ground plans. Here also there is an exceptional development of cavate lodges, and corresponding to this development an almost entire absence of cliff dwellings. From the large amount of data here a fairly complete idea of this phase of pueblo life may be obtained. This region is not equal to the Gila valley in data for the study of horticultural methods practiced among the ancient Pueblos, but there is enough to show that the inhabitants relied principally and, perhaps, exclusively on horticulture for means of subsistence, and that their knowledge of horticultural methods was almost, if not quite, equal to that of their southern neighbors. The environment here was not nearly so favorable to that method of life as farther southward, not even so favorable as in some northern districts, and in consequence more primitive appliances and ruder methods prevailed. Added to these advantages for study there is the further one that nowhere within this region are there any traces of other than purely aboriginal work; no adobe walls, no chimneys, no constructive expedients other than those which may be reasonably set