I will now consider vegetarianism from the standpoint of true food science, or the welfare of the physical man. It will be observed that in the lesson entitled "Evolution of Man," one of the first considerations taken up is the scientific discussion of man's natural adaptation to the use of flesh foods. By natural adaptation I mean Nature's evolutionary plan of fitting the physiological organism to the food man is able to procure. The organism of man will, to a certain extent, adapt itself to a given diet within the brief period of one generation, just as, in the long ages of evolution, the digestive organs of any species of animal become adapted to such diet as may be procured. Thus it is of especial importance for us to know the diet of primitive man at a time before his intellectual resourcefulness made it possible for him to gather his bill of fare from the four corners of the earth. [Sidenote: Primitive diet of man] The diet of our related anthropoid apes, of every primitive savage tribe, and of our ancestors, indications of which have been found in fossils and caves--all three throw light upon the subject. The consensus of these various studies indicates that the original or natural diet of man was one drawn chiefly from the vegetable kingdom, but not entirely so. Fruits, nuts, green vegetables, edible foliage, tubers or roots were all included in man's primitive diet. The foods of animal origin were varied, and consisted of such articles as birds, eggs, shell-fish, many insects, and other forms of lower animal life, of which our modern habit of eating frogs' legs, eels, escargots (snails), etc., is merely an inheritance. [Sidenote: Why flesh-eating is unnecessary] Since the digestive, the assimilative, and the excretory organs of man have been constructed from, and adapted to, the use of vegetables, it is obvious that the flesh of animals is unnecessary, especially in view of the fact that there is nothing in flesh that cannot be secured from the vegetable world in its best and purest form. Man's primitive diet does not prove that he is by nature a vegetarian, as is the cow, and therefore entirely unsuited to digest any material of animal origin. The anatomy of man's teeth and of his digestive organs, however, indicates that he is by nature a vegetarian, and that his digestive organs are prepared to dissolve and to assimilate a diet that is somewhat more bulky than that of carnivorous animals, but, on the other hand, less bulky than the diet of animals which subsist wholly upon succulent plants, as do the purely herbivorous species. [Sidenote: Food problem of the Aryan races]