14 ARON. 



Number Y, in the first fifty days, was given three times as much 

 food as number VI, the latter receiving 140 calories only (meat 10 parts 

 and starch 1 part) . The body weight of number VI increased about 200 

 grams, while number V gained 1,300 grams. In the next fifty days, 

 number V was given only 335 calories and the increase in weight was 

 750 grams. Number VI received a very slight increase (150 calories) 

 because of its greater body weight, and gained about 100 grams. 



The composition of the food was now changed, a mixture of 1 part of 

 starch and 2.5 parts meat being supplied. The proportion of protein 

 in the food seemed to me sufficient, about one-third of the total caloric 

 intake being furnished by protein. Number V, when receiving as 

 much as 480 calories, increased only slightly in weight; the animal 

 now had reached almost the stage of adult life, and the greater part of 

 the increase in weight was due to storage of fat and not to growth. 

 The intake of number VI was at first reduced to 135 calories. Owing 

 to the fact that the animal's weight still seemed to increase, I further 

 reduced the food to about 120 calories, which amount, I thought, would 

 furnish sufficient energy to keep the body weight constant. However, on 

 this diet the animal, instead of gaining weight, lost, especially toward 

 the last. 



The changes in appearance which the two dogs showed during the 

 course of the experiment are of great interest. Number V increased 

 in weight and size just as any other normal dog would and was a 

 fine looking, well nourished animal. Number VI resembled dogs num- 

 bered II and III of the first experiment, but the changes from the 

 normal were more pronounced. Although increasing slightly in weight, 

 the animal from day to day became thinner, but taller and longer. We 

 see here the paradox of an animal becoming emaciated while gaining 

 in weight. In the end, number VI seemed to be only skin and bones. 

 Nevertheless, the dog was quite lively, jumping around and performing 

 a really astonishing amount of muscular work. 



On the one hundred and seventy-fifth day of the experiment a photo- 

 graph of both dogs (Plate I) was taken, showing their general appearance 

 and relative size, the distance from the lens of the camera being the 

 same for both. The most surprising fact is that number VI, while 

 weighing only two-fifths as much as number V, seemed to be not very 

 much smaller. Indeed, the animal had grown all the time so far as 

 length of body and size of extremities were concerned. 



The following m'easurements taken on the one hundred and eighty- 

 third day show that, there is only a slight difference in length between the 

 two dogs, while the circumference of number VI is considerably less 

 than that of number V. 



