ANIMAL PRODUCTION. 771 



" The progress of the hydrochloric acid action and the total digestion is most 

 rapid in the albumin not heated beyond 75° C. . . . 



"The rate of digestion seems to progi'ess more evenly with the hydrochloric 

 acid action in the albumin heated up to 75° than it does in the others. . . . 



" The progress of the hydrochloric acid action and the digestion while pro- 

 portionately greater the longer the period of digestion, diminishes relatively as 

 digestion continues. . . . 



" It is quite evident, from the results discussed in this paper, that the Mett 

 tube method of standardizing ferments is an unreliable one unless special pre- 

 cautions be taken." 



The metabolism of fruit acids in warm, weather, B. F. Duckwall (Canner 

 and Dried Fruit Parker, 33 (1911), Xo. .>, in,. 3S, 4O). — A summary of data 

 regarding the niotabolism of fruit acids, and related topics. 



Colloidal-chemical analysis of the phenomena of absorption and secre- 

 tion — absorption in the intestinal tract, M. H. Fischer {Kolloidcheiii. Bcihefte, 

 2 (1911), Ao. 8-9, pp. 30'i-3-'i2). — An extended digest of data and discus.sion of 

 digestion from the standpoint of colloidal chemistry. 



Muscular work and protein metabolism, A. Pugliese (Biochem. Ztschr., 33 

 (1911), No. 1-3, pp. 16-29). — From studies of the nitrogen content and its dis- 

 tribution in muscles the author concludes that metabolic changes take place 

 either not at all or in very limited degree in muscular work. Practically all 

 the substances withdrawn from working muscles are substances widely dis- 

 tributed in the body and are not to be regarded as abnormal. 



The human machine, A. Bennett (New YcyrJc, [1911}, pp. 123). — In this 

 volume the author discusses training the mental powers with a view to increased 

 efficiency. 



ANIMAL PRODUCTION. 



The study of heredity, Y. IIaecker (Allgemeine Vercrbungslehre. Bruns- 

 wick, 1911, pp. X+392, pis. .'1, figs. 13'}). — This is a general treatise on heredity 

 based on results of recent investigations. The contents are grouped under the 

 following headings: Historical introduction, morpho-biological foundations of 

 the study of heredity. Weismann's theory of heredity and problem of the inher- 

 itance of acquired characters, experiments in hybridizing, and new morpho- 

 biological theories of heredity. 



A bibliography is appended to each chapter. 



Introduction to the study of heredity, E. Baur (Einfuhrung in die Expeii- 

 vicntelle Vererhungslehre. Berlin, 1911, pp. 293, pis. 9, figs. 80; rev. in Biol. 

 Centbl., 31 (1911), No. 16-17, pp. 543, 5.J//)- — A systematic treatise on heredity 

 from the modern standpoint, based mainly on investigations of recent years 

 with both plants and animals by experimental methods. 



A bibliography of 426 titles is appended. 



Introduction to the science of heredity, R. Goldschmidt (EinfiUining in 

 die Yererhimgsicissenschaft. Leipsic, 1911, pp. IX-\-502, figs. 161). — This is a 

 course of 20 lectures on heredity based on recent investigations. A bibliography 

 of over 500 references is appended. 



A coefficient of individual prepotency for students of heredity, J. A. Har- 

 Bis (Ainer. Nat., 45 (1911), No. 536, pp. 471-478). — A discussion of the con- 

 ception of prepotency and methods of measuring individual prepotency. Certain 

 biometric formulas used for other purposes are suggested as well adapted for 

 measuring the desirability of the Individual parents for breeding. 



On the formation of correlation and contingency tables when the number 

 of combinations is large, J. A. Harris (Atner, Nat., If5 (1911), No. 537, pp. 



