Xl . Scientific Proceedings 
6th hours was determined. The dog was then caused to run on a 
treadmill during the 5th hour and it was found that the quantity 
of nitrogen in the urine was the same as during rest. Therefore, 
mechanical work has no influence on the rate of absorption per 
hour or the intensity of protein metabolism per hour in a dog 
which has been given meat in large quantity. 
METABOLIC STUDY OF a-UREIDOISOBUTYLACETIC ACID. 
. By ALICE ROHDE. 
(From the Hooper Foundation, San Francisco.) 
The procedure described for the identification of .-ureido- 
8-phenylpropionic acid in the presence of amino-acids and of 
urea is found to be applicable to the identification of a-ureido- 
isobutylacetic acid under similar conditions. This uramino-acid 
was recovered in considerable quantity from the urine of a cat 
after slow, continuous injection of a saline solution of the material 
into the blood stream of the animal. 
CHANGES IN THE COMPOSITION OF MUSCLE OF SALMON 
DURING MIGRATION. 
By CARL H. GREENE. 
(From the Sheffield Laboratory of Physiological Chemistry, Yale University, 
New Haven.) 
The muscles of the salmon during the fast of the spawning 
migration show a great decrease in the amount of fat and protein 
present, with a corresponding increase in the water content. 
During the first part of the migration the fat shows the greatest 
decrease but with the beginning of the disappearance of the fat 
the protein catabolism becomes marked. On the spawning 
grounds the fish show great exhaustion of all food reserves in 
comparison to the initial condition. 
The organic extractives as a whole and the extractive nitrogen 
in particular show a general tendency to increase during the 
migration fast. There is no apparent relationship in the behavior 
of the organic and inorganic extractives. 
The amino nitrogen in the fat-free tissue increases from 61 to 
84 mg. per 100 gm. This increase is most marked calculated on 
