Society of Biological Chemists V 
changed during the passage of the blood through the active 
gland. 
In the earlier experiments the cow was disturbed by precautions 
which were afterward found to be unnecessary, and the results 
of the experiments differed according as the subjects were much or 
little disturbed before and during the collection of the mammary 
blood. When they were much disturbed, the mammary plasma 
had the same concentration of lipoid phosphorus as the jugular, 
but a higher concentration of inorganic phosphorus, and a corre- 
spondingly higher concentration of total phosphorus. When they 
were little disturbed, the mammary plasma had a lower concen- 
tration of lipoid phosphorus and a higher concentration of inor- 
ganic phosphorus than the jugular. 
These results are taken to mean that the precursor in plasma 
of both milk fat and milk phosphorus is either lecithin or some 
related compound. The ratio phosphorus: fat in lecithin is 
about 1:18, whereas it is a out 1:50 in milk. If, therefore, the 
mammary gland takes from the plasma enough lecithin or enough 
of some related phosphatide body to supply its milk with fat, — 
it gets with it more phosphorus than can be used for the milk, 
and the excess must be returned to the blood. These considera- 
tions are taken to explain the back-flow of inorganic phosphorus 
from the mammary gland to the blood, which occurred in all the 
experiments. The experiments indicate further that the dis- 
turbance of milking animals interferes with the taking up of 
phosphatide by the mammary gland, but not with the back- 
flow of inorganic phosphate from the gland to the blood. 
THE EFFECT OF COTTONSEED FLOUR ON ANIMALS, WITH PAR- 
TICULAR REFERENCE TO THE INORGANIC CONSTITUENTS 
OF WHITE RATS. 
BYE Gs COOK. 
(From the Bureau of Chemistry, United States Department of Agriculture, 
Washington.) 
Six separate groups of animals, each group consisting of 
twenty-four rats, twelve mice, and six guinea pigs, were fed for 
periods up to 6 months on (1) 25 per cent cottonseed flour bread, 
(2) 25 per cent cottonseed flour dough, (3) 40 per cent cottonseed 
