Diet is largely a matter of latitude. The whale blubber diet of the Esquimaux would be impossible at the equator, while the fruit and pulse diet of the tropics would prove totally inadequate to support life at the North Pole. Nature always prompts the individual to select the articles of food best adapted to his bodily needs, according to the climatic conditions; hence, when a man endeavors to live on the same dietary in the tropics that he has been accustomed to in the temperate zone, digestive disturbances are sure to follow. It is one thing to sit at home theorizing about dietetics and settling all the food problems (on paper) to one’s entire satisfaction; but it is quite a different matter to practically test the effects of different dietary tables under varying climatic conditions. The writer does not claim to be an expert dietician, but there are few spots on the habitable globe that he has not visited; scarcely an edible article that he has not partaken of; scarcely a known species of human being that he has not eaten with, except the Patagonians and the Esquimaux; so that he is not entirely without experience, and it may be just possible that practical experience thus gained may be as valuable as statistics compiled in an office from data collected from different sources. We often have the Eastern peoples (notably the Japanese and Hindoos) quoted as examples of physical health and endurance, and the adoption of a vegetarian diet urged on those grounds; but these extremists seem to lose sight of the fact that these peoples are the descendants of vegetarians for centuries past; that they have inherited the tastes of their progenitors, and have evolved their present physical condition through a long period of development along those lines. To say nothing of the impracticability of suddenly converting a nation to the principles of vegetarianism, radical changes abruptly undertaken are always productive of ill effects. It will help us to a proper understanding of the food question to consider right here what causes old age, or, rather, the physical signs of bodily infirmity that almost invariably accompany it. We are all familiar with the wrinkled body surface, the shrunken limbs and the stiffness of joints that particularly affect the aged, and are so accustomed to regard these outward manifestations of infirmity as inevitable, that few stop to inquire whether it is natural that this should be so. Undoubtedly, these are natural effects, being the result of the operation of natural law, but if mankind lived more in harmony with Nature, these symptoms should not manifest themselves before the age of ninety or a hundred, if even then.