1914] Scrgius Morgulis 265 



diet of meat, lard and boiled rice with an average caloric value of 

 70.8 cal. per kilo, or 75 per cent more than its minimum requirement. 

 On this allowance the dog was able to just maintain a constant body 

 weight. The average respiratory quotient, which was 0.79, indi- 

 cated that the dog oxidized, for its maintenance, fat and protein 

 primarily. 



After this normal base Hne had been estabhshed, the diet was 

 reduced to one-third of its former quantity, so that the animal was 

 getting 25.7 cal. per kilo instead of 70.8 cal. In the course of the 

 experiments its body weight diminished from 13.94 k. to 8.04 k. 

 It is obvious that, as the weight of the dog was gradually declining, 

 the caloric equivalent of the food supply per unit of body weight 

 was increasing. We found that, at the close of the underfeeding, 

 the animal was receiving 40.3 cal. per kilo. The loss of weight, 

 however, was remarkably uniform throughout the entire experi- 

 ment, following the course of a practically straight line with a 

 constant angle of slope. During the several weeks of underfeeding 

 a number of respiration experiments were perf ormed at more or less 

 regulär intervals and the changes in the basal metabolism followed 

 Step by Step. Within five days after the dog had been put on the 

 insufficient diet, the gaseous exchange was found to be 3.16 liters of 

 carbon dioxide and 4.36 liters of oxygen per hour, and a week later 

 3.01 and 4.03 liters respectively. Expressed in terms of energy 

 equivalents, the basal metabolism of the dog had diminished from 

 546.3 cal. to 458.9 cal. per day, or over 16 per cent. From this 

 point little change was observed in the basal metabolism, which 

 reached a minimum of 442.4 cal. during the next five weeks. The 

 greatest reduction in the expenditure of energy within this period 

 was less than 6 per cent. The respiratory quotients obtained in ex- 

 periments performed during that period, ranging from 0.73 to 0.76, 

 show that fat was the material chiefly concerned in the combustion. 



By this time the dog's weight had suffered a loss of over 30 per 

 cent, and the dog showed a number of other ill effects of the under- 

 feeding. When the first signs of physical debility had become ap- 

 parent, a new abrupt change occurred in the basal metabolism of the 

 dog. In the eighth week of underfeeding, the carbon dioxide pro- 

 duction and oxygen consumption per hour diminished to 2.59 and 

 3.41 liters, respectively. During the next two weeks the gaseous 



