By means of an apparatus developed particularly for the purpose, the author was able to make a study of the respiratory exchange in the elephant. This original investigation is associated with the important facts regarding the physiology of the elephant, including the relationship between the weight of the new-born elephant and that of its mother, necropsies, basal metabolism and similar factors. It is interesting to know that the average length of life of an elephant is probably about that of man. Many elephants sleep standing up. The elephant matures sexually at about 10 years of age and its period of gestation is about twenty months. A new-born elephant weighs about 200 pounds. A full-grown elephant drinks about 50 gallons of water a day, preferably warm. The total basal metabolism of the average elephant is 4,900 calories for twenty-four hours. A large elephant produces about as much heat as thirty men.