562 EXPERIMENT STATION RECORD. 



died after 5 to 7 weeks, and similar experiments with pigeons indicated that tlio 

 diet contained an insuflicient quantity of vitamins, which prevent beri-beri. 



The addition of from 2 to 6 per cent of dried brewer's yeast produced suc- 

 cessful growth and maintenance. 



In the authors' opinion, these experiments show that butter fat does not 

 stimulate the growth of young animals. It is intended to study whether yeast 

 alone without butter will produce normal growth in rats, and to isolate its 

 efficacious constituents. 



The resumption of growth after long-continued failure to grow, T. B. 

 Osborne, L. B. Mendel, Edna L. Ferry, and A. J. AVakeman (Jour. Biol. Chem., 

 23 (1915), No. 2, pp. .'i39-'f5.'t, figs. 5). — In the feeding experiments here reported, 

 a number of laboratory animals (rats) received a diet either quantitatively or 

 qualitatively insufficient for growth. This ration contained varying amounts of 

 protein and amino acids, starch, lard, butter fat, and " protein-free milk." 



The capacity to gi'ow — the growth impulse — it was found was retained and 

 exercised at periods far beyond the age at which growth ordinarily ceases. This 

 was evident on supplying an adequate diet, resumption and completion of 

 growth being obtained at an age of over o.jO days, although growth usually 

 ceases before the age of 300 days. Tlie animals were able to reach their full 

 size, and to exhibit normal procreative functions. Further details of the 

 study are summarized in part as follows : 



" The satisfactory resumption of growth can be attaino<l not only after 

 stunting by underfeeding but also after the cessation of growth which results 

 when the diet contains proteins unsuitable for the .synthetic processes of 

 growth or is low in protein. Growth in the cases referred to is resumed at a 

 rate normal for the size of the animal at the time. It need not be slow, and 

 frequently it actually exceeds the usual progress. 



"The size or age at which the inhibition of growth is effected does not alter 

 the capacity to resume growth. Even when the sujipression of gi'owth is 

 attempted for very long periods at a very small size (body weight) the 

 restoration may be adequate when a suitable diet is furnisheil. . . . 



"The period of growth may be gi'eatly prolonged by inadequacies in the 

 diet, so that growth becomes very slow without being completely inhibited. 

 Though the time of reaching full size is thus greatly delayeil, growth, as ex- 

 pre.ssed by suitable body weight, can ultimately be completeil even during the 

 course of long-continued retardati<in." 



On the basis of these observations the authors consider it reasonable to ask 

 whether the capacity to grow can over be lost unless it is exercised. 



Diet and its effect upon blood sugar, W. vo.v Moraczewski (Biochcm. 

 Ztschr., 11 (1915), Xo. .'f-5, pp. '26S-2SS). — The results are reported of an inve.s- 

 tigation to determine the inlluence of the ingestion of protein, fat, and carbo- 

 hydrate and also the effect of muscular work upon the content of blood sugar 

 in the human organism. The conclusions may be summarized in part as 

 follows : 



A diet containing an excessive amount of carbohydrate and deficient in 

 other constituents increases the content of blood sugar temporarily, while one 

 containing an excess of protein produces a slight, though permanent, increase. 

 On the ingestion of an excessive amount of a well-proportione<l diet the 

 carbohydrate is withmit influence on the blood sugar, but the protein and fat 

 have an insignificant though lasting effect. Tolerance for sugar seemed to 

 he increased by muscular work. 



Studies on blood fat.— I, Variations in the fat content of the blood under 

 approximately normal conditions, W. K. Bt.oor (Jour. Biol. Chan.. 19 (/.''/-}>. 

 No. 1, pp. l-2Jf, figs. 5). — The experiments reported are the first of a series 



