ANIMAL PRODUCTION". 161 



figs. 103; 2, i)p. 956-1823, figs. 121, tables 3).— The two volumes making up this 

 handbook contain articles contributed by a number of authors, among others 

 the following : The General Examination of Urine, by P. Mayer ; The Determi- 

 nation of the Inorganic Constituents of Urine, by S. Frankel ; The Study of the 

 Konnitrogeuous Organic Constituents of Urine, by C. Neuberg ; The Nitrogenous 

 Constituents of Urine, by A. C. Andersen ; The Chemical Examination of Feces, 

 by O. Schumm ; and The Calorimetry of Urine and Feces, by A. Loewy. 



Chapters are included giving directions for carrying on metabolism experi- 

 ments with man and animals, etc., as well as special chapters or sections on 

 milk colostrum and other body secretions or fluids. 



Some energy factors of the urine excreted after severe muscular exercise, 

 H. L. HiGGiNs and F. G. Benedict (Amer. Jour. Physiol., 28 (1911), No. 6, pp. 

 291-300). — The experimental work reported emphasizes the importance of study- 

 ing the carbon-nitrogen and calorie-nitrogen ratios in urine, and a method of 

 determining the heat of combustion of the carbon of urine is given. 



" The carbon-nitrogen and calorie-nitrogen ratios of a number of urines 

 passed after a severe, long-distance running race are reported. The values for 

 12 out of 18 urines were essentially normal ; the remaining 6 urines gave high 

 ratios, probably due to perverted protein metabolism. 



" In view of the fact that the calorie-carbon ratio is constant, the advantage 

 is pointed out of the development of either a volumetric method or a wet process 

 by which determinations of carbon in urine can be simply, quickly, and accu- 

 rately made." 



A method for the quantitative determination of fecal bacteria, H. A. 

 Mattill and P. B. Hawk {Jour. Expt. Med., 14 (1911), No. J/, pp. 433-U3).— 

 From results of which the data reported form a part it appears, according to 

 the authors, " that the amount of bacterial nitrogen in the feces is a valuable 

 index to intestinal conditions, and the method herein described is a simple and 

 satisfactory one for making this determination. It involves three serial cen- 

 trifugalizations of a 2-gm. sample of the fresh feces brought into suspension in 

 0.2 per cent hydrochloric acid. The bacterial suspension finally obtained is 

 concentrated and extracted by alcohol, and nitrogen is determined in the 

 precipitated material. The complete data on a given stool can be obtained in 

 about 5 days, and one operator can take care of 3 or 4 stools in duplicate 

 in 1 day. 



" On an absolutely uniform diet of simple and easily digested food during 

 a period of 3 to 4 weeks, the average amount of bacterial nitrogen in two sub- 

 jects was found to tte 53.9 per cent of the total fecal nitrogen, and this per- 

 centage, though higher than that obtained by workers heretofore, is probably 

 more nearly a true value for bacterial nitrogen, because no ether extraction 

 was employed. 



" The average daily amount of dry bacteria, calculated on the basis of the 

 nitrogen values, is 8.27 gm." 



ANIMAL PRODUCTION. 



Heredity in relation to evolution and animal breeding, W. E. Castle 

 (New York and London, 1911, pp. XII+ISJ/, pis. i//, figs. 20). — This work is 

 based on lectures given in 1910 at the Graduate School, Ames, Iowa, and at 

 the Lowell Institute, Boston, Mass. There is a brief introduction to the science 

 of genetics, which is followed by a full and lucid treatment of the application 

 of Mendel's law and its probable value in the formation of new and improved 

 breeds better adapted to the conditions of present-day agriculture. It is 

 pointed out that an empirical knowledge of breeding, which has been the main 



