The student of Comparative Religion seeks answers to these and similar questions. A vast field of inquiry is at once opened before him. It embraces practically every continent, people, and tribe on the face of the globe. It begins in the last period of the great ice age, when men lived in this country in the company of the elephant, the rhinoceros, and the mammoth, and hunted their game through {20} Germany, Belgium, and France. In dim recesses of the caves they painted the deer, the bison, the antelope and the wild boar, under conditions which imply some kind of mysterious or holy place. They buried their dead with care, and though we can ask them no questions we may infer with much probability that they celebrated some kind of funeral meal, and deposited implements and ornaments in the grave for the use of the departed in the world beyond. In one case hundreds of shells were found buried with the skull of a little child. Similar usages may be traced through the slow advances of culture to the present day. Death is an element of universal experience; and it is not unreasonable to suppose that if the negroid peoples of Western Europe had worked out some view of its meaning and consequences, there were other things to be done or avoided out of fear or reverence for the Unseen. The first objects of comparison are thus found in the outward acts which fall more or less clearly within the sphere of religion, the places where these are performed, the persons who do them, the means required for them, the occasions to which they are attached. These all belong to the external world; they can be observed and recorded, even though we may not be sure what they mean. When they are brought together, a series of gradations of complexity can be established, while a common purpose may be traced through all. {21} From the negro who lays his offering of grain or fruit at the foot of a tree with the simple utterance, "Thank you, gods," to a great Eucharistic celebration at St. Peter's, a continuous line of ritual may be followed, in which the action becomes more elaborate, the functions and character of the officiating ministers more strictly defined, the accessories of worship more complicated. This corresponds to the enrichment and elevation of the ideas and emotions that animate the act, as that which is at first performed as part of tribal usage and ancestral custom acquires the force of divine institution and personal duty.