460 EXPEKIMENT STATION EECOKD. 



"A species sbould not be described as new on account of a deviation from tlie 

 proportions of knov/n species unless tliat deviation is great and fundamental. 

 Tlie space occupied by the reproductive organs should not be considered, and 

 little dependence should be placed on the width of the body. Fl'om four to ten 

 individuals should always be studied and the observed range recorded. In this 

 way the varying proportions of the different species can be used in the identi- 

 fication of collected specimens. An individual should never be identified, how- 

 ever, on the basis of the formula alone or of the proportions alone." 



FOODS— HUMAN NUTEITION. 



Contribution to the knowledge of the ripening of meat, H. Kren (Wiener 

 Tierdrztl. Monatsschr., 1 {191Jf), No. 12, pp. 585-589). — Analytical data are 

 reported regarding samples of meat kept in cold storage from 1 to 8 days. The 

 results indicate, in the author's opinion, that the ripening of meat depends upon 

 the hydrolytic cleavage of the protein. 



Studies on the digestibility of milk and means of increasing it, L. Gaucher 

 (Bill. G6n. TMr. M6cl. et Chinirg., 167 (19 W, No. U, pp. 371-381; abs. in 

 Zentbl. Biochem. u. Biophys., 17 (1914), No. 1-2, pp. 29, 30). — In the opinion of 

 the author the difficulty experienced by individuals in digesting cows' milk is 

 due to the coagulation of the casein in the stomach in large masses rather than 

 in finely divided particles. He recommends that antirennet of calf or horse 

 serum be added to the milk to secure the formation of a finely divided curd in 

 the stomach, as the casein in this condition passes readily into the intestines 

 for digestion. 



The influence of milk feeding on mortality and growth, and on tlie char- 

 acter of the intestinal flora, L. F. Rettger (Jour. Expt. Med., 21 (1915), No. 4, 

 pp. 365-388). — This paper reports a large number of feeding experiments with 

 laboratory animals (chicks and rats), some of which have been previously 

 noted (E. S. R., 33, p. 273). 



No difference was observed in the relative value of ordinary sour milk and 

 of the so-called bulgaricus product. The milk and lactose diet exerted a great 

 influence upon the character of the intestinal bacteria in the case of both white 

 rats and chicks which is attributed to the lactose contained in the milk, as other 

 carbohydrates than lactose failed to exert this influence. 



" The ingestion of foreign bacteria, even in large numbers, does not of itself 

 bring about an elimination or displacement of the common intestinal micro- 

 organisms. Vastly more important is the influence of diet, especially milk 

 and lactose. The feeding of Bulgara tablets or other preparations which con- 

 tain as the supposedly active agent the bacillus of IMetchnikoff and IMaze. with- 

 out due regard to the use of milk, can, therefore, be of little, if indeed of any, 

 value. The beneficial effects which it is claimed have been derived from the 

 use of yoghourt, and other oriental sour milk products have in all probability 

 been due to the milk as such, rather than to the bacteria which they contained." 



The germicidal efEect of lactic acid in milk, P. G. Heinemann (Jour. Infect. 

 Diseases, 16 (1915), No. 3, pp. 479-486). — In the experiments here reported 

 samples of sterile milk containing different concentrations of lactic acid were 

 inoculated with BaciUus coli, B. dysenterice, B. typhosus, and B. paratypJwsus B, 

 .nnd incubated. Bacteriological examinations of these samples were then made 

 to determine the growth of the organisms. 



From the results of these experiments the author concludes that, although 

 resistant strains may survive, the growth of pathogenic bacteria in milk is 

 imlikely in the presence of 0.6 per cent of lactic acid. " The smaller the initial 

 amount of lactic acid, the more likely is the growth of acid-tolerant strains. 



