36 ARON. 



is very limited. For instance, in the case of dog II it can not have 

 amounted to more than 20 or 25 calories per day ; in that of dog XI, to 

 10 calories at most. The amount of energy which the animals could draw 

 from their own bodies is hardly sufficient to give them all the energy 

 required according to the surface law. Furthermore, we see that dog 

 A maintained its body weight of about 2,200 grams with an intake of 

 only 170 calories, whereas 190 were required, and yet we must assume 

 that this animal had no further reserve stuffs to burn. I have already 

 mentioned that the values for energy required for maintenance obtained 

 by the general formula seem to be at least 10 per cent higher than those 

 found, for instance, by Eubner in some of his experiments. On the 

 basis of these values dog A, weighing 2,800 grams, receives sufficient 

 energy from 170 calories, but in the case of dogs II and XI, the intake of 

 energy plus the highest possible amount obtained from the body itself 

 can scarcely cover the requirement. I conclude that emaciated animals 

 show a low demand for energy. The opposite opinion generally prevails, 

 namely, that an emaciated young animal (child) needs more energy per 

 kilo for maintenance than a well-nourished one. (Lissauer, Schloss- 

 mann.) 



In the Philippine Islands the prevailing temperature may have an 

 influence. Emaciated animals in a temperate climate, where they are 

 kept at from 15° to 20°, possibly may lose more heat and therefore re- 

 quire more energy for maintenance than in Manila, where the temper- 

 ature rarely falls below 25°. At the time dog VI was most emaciated, the 

 temperature varied between 28° and 35°. This point is worth men- 

 tioning because it may explain certain divergencies. 



BIOLOGICAL CONSIDERATIONS CONCERNING THE SUPPRESSION OF GROWTH BY 



RESTRICTING THE FOOD. 



In the course of our experiments we could distinguish two periods : 

 First period. As long as there is a reserve of energy in the body, the 

 animal draws on this and, while starving parts of the body, continues to 

 grow. This "starvation" does not produce a loss in weight as it would 

 with an adult animal, but is" compensated, or even overcompensated for 

 by an increase in the weight of the skeleton and by an increase of the 

 water content of the body. (Verwasserung.) Second period. This 

 begins when the animal has reached the last stage of emaciation, in which, 

 if the intake of energ}' only meets the demand required for maintenance, 

 no growth takes place and both weight and growth are at a standstill. 



During the first period, constancy or slight increase of weight in- 

 dicates inanition, during the second period, cessation of growth. 



It is only possible to suppress growth entirely by restricting the food 

 when an animal is so emaciated that it has no further reserve stuffs to 

 draw on. From a biological standpoint there are two forces in a growing 



