862 EXPERIMENT STATION RECORD. 



per square meter of body surface and a remarkable uniformity per square 

 meter of body surface per unit of length. This constancy is such as to permit 

 the establishment of a factor which indicates that when the square meter of 

 body surface as computed from the body weight is divided by the length the 

 metabolism per unit is 12.65 calories. From a study of the effect of tempera- 

 ture changes on the basal metabolism and the amount of available breast secre- 

 tion in the first week of life, certain procedures for the conservation of energy 

 and supplemental feeding are suggested. 



Acceleration of growth after retardation, T. B. Osborne, L. B. Mendel, 

 Edna L. Ferry, and A. J. Wakeman {Amer. Jour. Physiol., 40 (1916), Xo. 1, pp. 

 16-20, pis. 2). — Curves are given illustrating the accelerated growth of a number 

 of albino rats in which growth had previously been retarded either intention- 

 ally by the character of the diet or incidentally as the result of a failure on 

 the part of the animals to eat enough of a supposedly adequate ration. The 

 authors conclude that " after periods of suppression of growth, even without 

 loss of body weight, growth may proceed at an exaggerated rate for a consider- 

 able period. This is regarded as something apart from the rapid gains of 

 weight in the repair or recuperation of tissue actually lost. Despite failure 

 to grow for some time the average normal size may thus be regained before 

 the usual period of growth is ended." 



Studies in water drinking. — XX, The relationship of water to certain life 

 processes and more especially to nutrition, P. B. Hawk (Biochcm. Bui., S 

 (1914), No. 11-12, pp. If20-Jf3.'f). — In this summary and digest of data, continuing 

 previous work (E. S. U., 34, p. 703) the author describes the physiological needs 

 of the body for water from both the physical and the chemical standpoints. 

 With regard to water drinking at mealtime, he concludes that for the normal 

 individual "the drinking of a reasonable volume of water wilh meals will 

 promote the secretion and activity of the digestive juices, the digestion and ab- 

 soiption of the ingested food, and will retard the growth of intestinal bacteria 

 and lessen the extent of the putrefaction processes in the intestine." 



The relation of salivary to gastric digestion, L. A. I. Maxwell {Biochcm. 

 Jour., 9 (1915), No. 3, pp. 323-329; abs. Jour. Cliem. Sac. [Lomlon], 108 (1915), 

 No. 637, 1, p. 102Jt). — From the experimental data here reported, the author con- 

 cludes in part that unboiled starch does not liinder peptic digestion, but that 

 all cooked farinaceous foods do this unl(<ss first subjected to salivary digestion. 



Gastrointestinal studies. — XII, Direct evidence of duodenal regurgita- 

 tion and its influence upon the chemistry and function of the normal human 

 stomach, AV. II. Spencer, G. P. Meveu, M. E. Rehfi'ss, and P. B. Hawk (Awcr. 

 Jour. Physiol., 39 (1916), No. 4, pp. 459-^79, figs. i2).— The experiments liere 

 reported were undertaken to determine whether or not duodenal regurgitation 

 does occur, as evidenced by the presence of some of the constituents of the 

 duodenal secretions in the samples of material removed from the stomach. Of 

 these constituents, trypsin was regarded as the most satisfactory indicator. 

 Quantitative determinations of trypsin were made in samples of the stomach 

 contents, obtained by fractional removal through the Rohfuss tube as has been 

 described in earlier papers of this series. Tlie samples were taken after the 

 introduction into the stomach of hydrochloric acid; vinegar; water; sodium 

 bicarbonate solutions of various strengths; and a small Ewald meal, both with 

 water and with sodium bicarbonate solutions. From the results of these tests, 

 which are reported in detail, the following conclusions are drawn : 



"A tryptic enzym is almost constantly present in the fasting and digesting 

 contents of the normal human stomach. . . . [This] is deduced to be trypsin 

 regurgitated from the duodenum. 



