164 EXPEKIMENT STATION KECOKD. 



A note concerning- the influence of diets upon growth, F. G. Hopkins and 

 A. Neville (Biochem. Jour., 7 {1913), No. 1, pp. 97-99). — A brief preliminary 

 report of data, to be published in full later, concerning the influence of such 

 complex substances as lipoids on growth, which disagrees with results obtained 

 by other workers. 



Influence of food on the amylase content of human saliva, C. L. Evans 

 {Biochem. Ztschr., J,S {1913), No. 6, pp. 452-4^/7 ).— This progress report of ex- 

 periments on the diastatic strength of human saliva under different conditions 

 of diet, starvation, etc., is summarized by the author as follows : 



The amount of amylase in saliva is increased after a meal containing the three 

 principal nutritive ingredients. The increase begins from 20 to 30 minutes 

 after eating, lasts 2 or 3 hours, and then, having reached its maximum, grad- 

 ually decreases until the next meal. If a meal is omitted, the activity of the 

 saliva remains constant after the effect of the last meal has passed off. When 

 food is chewed, but not swallowed, no increase in the amylase content is ob- 

 served, nor does any occur after a meal consisting entirely of protein. 



The simplest explanation of these phenomena seems to be found in the 

 assumption that they depend on a hormone developed in the stomach through 

 the action of the products of carbohydrate digestion upon the mucous membrane 

 of that organ. The chief cause of the increase of amylase in the saliva is the 

 increased amount of enzyms in the parotid saliva, which possesses four times 

 the activity of the remaining saliva and is nearly half as great in volume. 



The diflferences in the peptic dig-estibility of wheat and oats, M. Klotz 

 {Monatsschr. Kindcrhcillc, 11 {1912), No. 1, pp. 29-S7 ; abs. in Zentbl. Expt. 

 Med., 2 {1912), No. 4, P- 152). — It having been shown that oat starch undergoes 

 cleavage with diastatic ferment more readily than wheat starch, additional 

 exiDeriments were made with peptic ferments. These showed that the protein 

 of wheat flour was much more thoroughly digestible by peptic and tryptic fer- 

 ments than the protein of ground oats. 



Results of a different character were obtained when starches made from the 

 two grains were used, the protein of the oat starch being practically as digest- 

 ible as that of the ground oats and more digestible than the protein of the wheat 

 starch. From this it appears that the wheat contains two different proteids, 

 of which one is found in the starchy portion, and that this is less readily 

 attacked by ferments. 



The rate of protein catabolism, E. P. Cathcaet and H. H. Green {Biochem. 

 Jour., 7 {1913), No. 1, pp. 1-17). — The protein foods studied were added on a 

 particular day to diets of low, medium, and high protein content upon which 

 the subject was maintained ^r several days before and after the special foods 

 were added. The total output of sulphur and nitrogen in the excreta was deter- 

 mined, as were the creatin and creatinin. 



The results of the investigation showed the sulpbur-containing part of the 

 protein to be more rapidly catabolized and the sulphur more rapidly excreted 

 tban the nitrogen after ingestion. When protein is superimposed on a low pro- 

 tein diet, part of the nitrogen is retained and " apparently stored in the tissues 

 as a pabulum of uniform composition." From the study of the ratio of sulphur 

 to nitrogen, the authors conclude that the increase in the output of sulphur and 

 nitrogen after a protein meal is due to the catabolism of the actual material 

 ingested and not to the displacement of worn-out protoplasm from the tissues. 

 No effect of the superimposition of protein was noticed on the output of creatinin. 



The physiological nitrogen minimum, K. Thomas {Arch. Anat. u. Physiol., 

 Physiol. AM., 1910, Sup., pp. 2Ji9~285). — This article includes a general discus- 

 sion of minimum nitrogen metabolism under different conditions and the report 

 of experiments made by the author, some for extended periods with himself as 



