While some of the arguments offered in sober earnestness in support of abstinence from flesh foods are suggestive of mental invalidism, others demand serious consideration and an answer based upon scientific understanding. In the former category we may place the assertion that the anthropoid apes, regarded as cognates of our ancestors, live on fruits, nuts and cereals, and that this fact proves that such a diet is especially suited to the nutrition of man. One may well argue that if a change to meat eating in the era of the cave man has caused or permitted him to develop mentally and physically into what the human race is to-day, this change in dietary habits may have been indeed a great piece of good fortune. The low development of other omnivorous types of animals weakens the force of this argument. We may also retort that it is no more advisable to permit the apes to be our guides in dietetics than in certain other ways of living. It is, however, well known that the apes eat insects, worms, eggs, small birds and such other animals as they are able to capture, and that they also eat the leaves of certain plants.

There is little comfort for the vegetarian enthusiast in the comparison of the anatomical structure of the alimentary tract of man with that of animals whose diets are of different types. The dentition, the size and shape of the stomach, intestine and cecum of man clearly indicate suitability for a mixed diet. To the esthetic argument the meat eater may reply that he includes sufficient fruits, nuts and cereals in his diet to permit him to be inspired by the beauties of Nature. To the statement that a refined person cannot eat meat until it is cooked, and its flavor changed so as to disguise its origin, the reply may well be made that many fruits and vegetables are not at all appetizing until cooked and so flavored as to increase their palatability. The argument which was at one time considered to be irrefutable and to be of sufficient force to condemn meat eating rested on the content of uric acid forming substances (purins) in flesh foods. Chemical studies have, however, shown that there are very nearly comparable amounts of purins in many vegetable foods, such as lentils, oatmeal, beans, asparagus, and notably in tea and in coffee.