The dietetic career of the evolving man from simian times onwards has been characterized by three signal advances, each of which has greatly augmented his supply of food. Before considering these a word may be said as to a convenient method of denoting the successive grades, or stages, in man's evolution from his simian ancestors. This is by reference to cranial capacity (see Fig. 1). Assuming the latter in the common ancestor of man and the great apes to have been 300 c.c, and in the average European of to-day to be 1,500 c.c, we may mount upwards to the 1,500 c.c. by successive grades of 100 c.c, or, striking out the noughts, from 3 to 15. Thus we may speak of a third-, fourth-, and fifth-grade Simian; of a sixth-, seventh-, eighth-, and ninth-grade Homo-simian; and of a tenth-, eleventh-, twelfth-, thirteenth-, fourteenth- and fifteenth-grade Man.

The Evolution Ladder, showing Man's Ascent from the Ape.

Fig. 1. - The Evolution Ladder, showing Man's Ascent from the Ape.

The third rung, 3, represents the position of man's primitive anthropoid precursor, with a cranial capacity of 300 c.c. The highest rung, 15, represents the position of modern civilized man, with a cranial capacity of 1,500 c.c. The dignity of manhood was attained, it is assumed, at the tenth rung - i.e. when the cranial capacity was 1,000 c.c. The simian stage, or stage of the man - like apes, extended from the third to the fifth rung; the homo-simian stage, or stage of the ape-like man, from the fifth to the tenth; and from the tenth rung onward is represented the stage of man.

The first great dietetic advance made by the evolving man occurred (say, at the tenth grade, see Fig. 2) when the genuine hunting and fishing stage was entered upon - when man began, i.e. systemically to employ artificial aids in capturing his animal food, and thus came greatly to increase its supply, and to be correspondingly less dependent upon vegetable food. Until he had in this way developed into a skilled hunter and fisher, he could procure none of the larger game, except by an occasional lucky chance, and only a very limited quantity of fish.

The second advance came (say, soon after the eleventh stage) when he began to subject his vegetable food to preparation, such as sun-drying, grinding, maceration, and above all cooking, the last process probably not being adopted until after he had learnt to employ the three more primitive methods. The employment of cookery, by converting the innutritious into the nutritious, led to a considerable increase in the supply of vegetable food and opened the way to the cultivation of grain and roots otherwise comparatively useless.

The third advance - preceded by the minor step of learning the secret of storage against seasons of dearth - occurred when man began (at about the thirteenth stage) to cultivate the plants and to breed the animals he had come to value. Once he had fairly entered on this stage he in one bound increased his food supply a thousandfold, and became able to multiply and progress in a manner hitherto quite impossible.

the Three Great Dietetic Advances made by Man in the Course of his Philogeny.

Fig. 2. - Diagram indicating the Three Great Dietetic Advances made by Man in the Course of his Philogeny.

We are now in a position to tabulate the following epochs and periods. Thus : -

1. The pre-cookery epoch. -

From the ape stage to the invention of cookery, 3rd-l1.25th grade.

The Simian period (3rd-5th grade ).

The Homo-simian period (5th-10th grade).

The Early Hunting period (10th-11.25th grade).

2. The pre-cibicultural cookery epoch. - From the invention of cookery to the introduction of agriculture and the breeding of animals for food (l1.25th-13.5th grade).

The period of Migratory Agriculture and

3. The cibicultural epoch. - From the time man began to produce his food artificially to the present day.

The period of Stationary

Agriculture Early./Late.

These diet periods we will now consider seriatim.

1. The Simian Period

Our study of the food of the primates enables us to draw the following deductions regarding that of our simian precursors (3rd-5th grade), beings akin to the surviving great apes. The descendants of animals of herbivorous habits, they were themselves in the main frugivorous, subsisting chiefly on concentrated vegetable food, such as seeds, nuts, and berries, as well as on the less concentrated luscious fruits, leaves, and young shoots, and probably also on roots (which were scratched or pulled up), gum, honey, and the bark of certain trees. Much of the vegetable food, owing to the large admixture of cellulose, was dense and coarse, and of a kind which would be highly disagreeable to the palates of their human descendants from the predominance of sour, bitter, and acrid principles. The animal food consisted of grubs, caterpillars, ants, ants' eggs, snails, insects (e.g. spiders, grasshoppers, beetles, and the like), reptiles (e.g. lizards, snakes), birds, birds' eggs, the smaller mammals (e.g. rats and mice); possibly also of shell and other fish from the lakes and streams.

2. The Homo-Simian Period

The next period (5th-10th grade) saw the simian prehuman struggle upwards from ape to man. He gradually spread from his cradle-land in Southern Asia or Northern Africa over the then existing Indo-African continent, leading, we may conjecture, a comparatively stationary or non-nomadic life, and subsisting chiefly on raw vegetable food. As his intelligence increased, however, and with it the means of procuring animal food, he became less and less a vegetable feeder and more and more carnivorous, though he was at this time able to secure only the smaller animals and a limited quantity of fish, being as yet without hunting weapons and fishing tackle. With this animal addition to his food he naturally came by degrees to abandon, and thus to lose the power of digesting the most indigestible and unpalatable forms of his vegetable supply.