Observations of these relatively most primitive tribes--and this is especially worth noting---show them to be remarkably similar. If we read a description of the characteristics, habits, and customs of the Negritos of the Philippines and then pass on to the Malaccans, to the Semangs and Senoi, or, further, to the Veddahs of Ceylon, we constantly meet with almost the same phenomena, there being but slight differences depending on the specific character of the natural environment. We are thus in possession of data that are now observable. The statements and conclusions which these enable us to make are more than mere speculations with regard to the past; and they are more than inferences drawn from the silent fragments of the bones and from a few of the art products of primitive man. According as the phenomena are simpler in character and require fewer antecedent conditions for their explanation, may we be confident that we are really dealing with primitive conditions. This in itself implies that the criteria of primitive culture are essentially _psychological_ in nature, and that racial characteristics and original tribal relationships are probably negligible so far as this question is concerned. A culture would be absolutely primitive if no antecedent mental development whatsoever could be presupposed. Such an absolute concept can never be realized in experience, here any more than elsewhere. We shall, therefore, call that man primitive in the relative sense of the term--our only remaining alternative--whose culture approximates most nearly to the lowest mental achievements conceivable within the limits of universal human characteristics. The most convenient measure of these achievements, and the one lying nearest at hand, is that afforded by _external_ culture, as expressed in dress, habitation, and food, in self-made implements, weapons, and other productions serving to satisfy the most urgent needs of life. 2. THE CULTURE OF PRIMITIVE MAN IN ITS EXTERNAL EXPRESSIONS.