, select his entire bill of fare
from the vegetable kingdom. That this may be done successfully, that is,
that a man may live on a diet, no part of which is drawn from the animal
kingdom, has been abundantly proven. The experience of many millions of
human beings in India and other Oriental countries who abstain from the
use of flesh on religious grounds, and to whom cow's milk is almost a
novelty, is a practical demonstration of the fact that the vegetable
kingdom is able to supply to human beings everything required for
complete nutrition.

It is true that some years ago Slonaker, of Leland Stanford University,
in an animal feeding experiment in which one group of rats was fed a
mixed diet and the other exclusively on food stuffs of vegetable origin,
found that his vegetable feeding rats, although for a few weeks showing
themselves superior to the mixed feeders later developed unmistakable
evidence of malnutrition and physical inferiority.

Some years later, however, McCollum of Johns Hopkins, then of Wisconsin
University, demonstrated conclusively that by making a proper selection
of vegetable foodstuffs, rats may live and thrive indefinitely on a diet
wholly derived from the vegetable kingdom. In connection with this and
other similar experiments, McCollum made the interesting discovery that
when an animal's bill of fare is to be wholly drawn from the products of
plant life it is necessary, in order that the animal shall be fully
nourished, that all parts of the plant should be eaten. His experiments
demonstrated that if animals are fed upon seeds, alone they undergo
physical depreciation, do not obtain full growth, are unable to
reproduce or nourish their kind, and ultimately perish. In like manner,
roots are found to be incapable of bringing an animal to full
development and sustaining its life indefinitely. It was found that to
be well nourished the animal must eat in suitable proportions, variable
within considerable limits, seeds or fruits and leaves. The great
importance of the green leaf as a complement of other foods has been
clearly shown.

Experiments by McCollum, as well as those of Osborne, Mendel, and
numerous other investigators in the same line of research, have made
clear several new and highly important facts in the physiology of
feeding.

They find that foods contain certain subtle elements known as vitamines
which are absolutely essential to the full development and prolonged
life of an anima