There is an exact agreement between the skeleton of man and the higher apes—all the bones corresponding, each to each, while there is a great dissimilarity between man and any other animal whatever. The nerves, the viscera, the spleen, the liver, the lungs, the brain, the skin, nails and hair—all present the closest possible analogy and similarities. The eyes are strikingly similar, while the chemical and microscopical character of the blood is also very similar in man and the higher apes. This fact is of especial importance and significance, when we bear in mind that only apes and men are subject to certain blood diseases—to which all other animals are impervious. In structure, as in habits, man and the apes are in many respects remarkably alike, and proportionately dissimilar to all other animals.
CHAPTER III
THE ARGUMENT FROM PHYSIOLOGY
“After structure—function!” Having seen in the last chapter that man is constructed throughout for a diet composed entirely of fruits, nuts, grains, and other non-flesh foods, we now turn to a consideration of the functions of the various organs of the body—the chemical composition of the organic tissues, secretions, etc.—in order to see if these will further bear us out in our argument. There can be no question that the most important argument of all, on this subject of diet, is the argument based upon comparative anatomy—since that argument places man in his right class immediately, and in a manner that cannot be evaded by any amount of argument. But other aspects of the question are also of importance, and afford strong proof of the natural character of man’s diet. The next argument we should consider, therefore, is the physiological, and we shall first of all consider the secretions.
The Saliva.—The differences between the saliva of man and that of any of the carnivora is striking. In man, this secretion is alkaline—though only slightly so, in a healthy man. Nevertheless, that is its normal reaction, and to this there is no exception. In the carnivora, on the other hand, the reaction is acid, and because of this fact is capable of dissolving the food more or less whole, and without the long process of mastication necessary for the herbivora and frugivora. The saliva in the human being effects many chemical changes in the food—notable among these being the conversion of starch. Were man intended to live on flesh, the saliva would be acid also—instead of alkaline as it is.
The Gastric Juice.—Dr Schlickeysen says of this:[10]
“A leading element of the gastric juice is lactic acid. This excites a slight fermentation of the chyme, and thus exerts an influence upon the digestion of vegetable, but not upon that of animal, food. It is far too weak to act upon the fibres of animal flesh. All fats are insoluble in water, spirits of wine, and acids. Flesh, when eaten by man, tends to undergo a process of decay in the stomach, causing a scrofulous poisoning of the blood. In this unnatural action lies the cause of many complaints and disturbances of the system: as bad breath, heartburn, eructions and vomiting. In the case of the carnivora, the gastric juice exerts a decomposing influence upon flesh, and causes its assimilation and excretion. Since the pancreatic juice of the duodenum, into which the chyme passes from the stomach, bears a close resemblance to the saliva, it follows that the chyme here, also, can have only a slightly acid property, which it indeed can only have when it is of a vegetable character. Bile, which is here poured into the intestines, has only a slight alkaline reaction, and its use seems to be limited to the prevention of decay; which, however, can only occur in the case of flesh-food; so that the effort of nature to maintain flesh-food in its proper condition by the secretion of bile must be excessive, and must eventually cause an excitement and weakening of the whole organism.”