less than pedantry rather than the work of serious investigation. The religious idea in man, whether observed in the darkest heathenism or partially enlightened civilization, has always associated a place of sanctuary with the conditions of elevation and separateness. It matters not whether you apply the rule to the practices of the most obscure antiquity, where a hill or natural eminence was the sanctuary of an idol, the residence of a god, or examine the motives which prompt the erection of the dome of a St. Paul or a St. Peter’s, or coming nearer home, analyze the reasons for the construction of the ordinary church spire, the same inexplicable intuition is found at the bottom of them all. The simple mound so common in the northern and central region of the United States, represents probably the first attempts at the imitation of nature in providing a place of worship. In the absence of hills and natural eminences on great plains like the prairies of the North-west (for instance in such cases as are cited on pages 28 and 29), nothing would be more natural than the construction of an artificial hillock, especially if the elements and nature were the objects of worship. The next step might have been again a copy or an imitation, but instead of choosing a subject from inanimate nature, an advance is made in the artistic scale, and the animal kingdom furnishes not only one but varied models for reproduction. The custom among savage tribes of personifying the deity, of dressing him up in some form, tangible and visible, was especially characteristic of the mythology of the Nahua nations of Mexico. It is not necessary to go to Egypt, or India, or China to find animals of various kinds dedicated to and associated with the national gods, for in the Maya and Nahua mythologies, as well as in the traditions of some of the wild tribes of the Pacific coast, the serpent, the coyote, the beaver and the buzzard play an active part. The erection of religious structures representing animals no doubt sacred to the Mound-builders, was carried on to a remarkable extent in Wisconsin. These strange works probably indicate the second step in their scale of architectural progression. In the Ohio Valley, while the ordinary mound is found in great numbers, and a few instances of animal mounds occur, three new architectural features present themselves in marked prominence, all of which are artistically in advance of those existing in the North and North-west. These are the enclosures, the truncated mounds, and principally the truncated pyramids, all of which are a departure from the strict imitation of nature, and exhibit the gradual growth of the architectural idea and the outcropping of the notion of utility. South of the Ohio Valley the animal mounds disappear altogether and the truncated mounds grow less common, while the truncated pyramid, the highest artistic form, with its complicated system of graded ways and its nice geometrical