ANIMAL PRODUCTION. 365 



The sex-determining factor in animals, S. Kowalewsky (Biol. Centbl., 31 

 (J911), No. 18, pp. oSO-592, figs. 2). — A contribution to tlie voluntary determi- 

 nation of sex in birds and mammals. 



Data are presented in support of the theory that the rate of oxidation at 

 fertilization and in the early stages of cleavage is a factor in the determina- 

 tion of sex. In guinea pigs and rabbits female fetuses were found in that por- 

 tion of the uterus which recelAed the greatest supply of blood, whereas males 

 were in the less richly nourished portions. Subcutaneous injections of alcohol 

 led to the production of a preponderance of males in guinea pigs. These and 

 other factors are brought forward as mdicating that poor nutrition favors the 

 production of males. 



The hereditary material and the cell as the basis of heredity, A. Peenant 

 (Jour. Anat. et Physiol. [Paris], J/J (1911), No. 1, pp. 1-59, jigs. 8). — A general 

 summary of information on this topic. A bibliography is appended. 



A note on certain biometrical computations, R. Pearl and Lottie E. 

 McPheters (Amer. Nat., 1/5 {1911), No. S'lO, pp. 756-760). — Tables are given of 

 hitherto unpublished sums of logarithmic functions which can be used for fitting 

 growth curves. They were originally made in studying the functions of suc- 

 cessively laid eggs, as previously noted (E. S. R., 21, p. 269). The use of the 

 tables in fitting curves by the method of least squares is illustrated by concrete 

 examples based on measurements of eggs. 



The doctrine of evolution; its basis and its scope, H. E. Ckampton (New 

 York, 1911, pp. IX-\-311). — This volume consists of a series of lectures delivered 

 as the Hewitt lectures of Columbia University at Cooper Union, New York City, 

 1907. It treats of the essential characteristics of living things and the factors 

 concerned in the evolution of species. 



The study of likeness and relationship in hybridization, PI. Poll (Arch. 

 Rassen u. Gessell. Biol., 8 (1911), No. 4, pp. J,17--'f37, pis. 2).— A discussion of 

 various degrees of sterility, particularly those which occur between diffei-ent 

 species of birds. 



On the inheritance of acquired characters: A hypothesis of heredity, 

 development, and assimilation, E. Rignano, trans, by B. C. H. Haevey (Chi- 

 cago, 1911, pp. I/IS). — The author points out that Weismannism is untenable 

 because it does not provide any satisfactory theory of the mechanism of in- 

 heritance and because it is not in accord with the biogenetic law that ontogeny 

 is a recapitulation of phylogeny. Also, both the preformistic and epigenetic 

 theories of development are unsatisfactory, the former because it does not 

 account for the inheritance of acquired characters, and the latter because it re- 

 quii-es the rejection of nuclear somatization. He, therefore, suggests a dynamic 

 memory theory, called centro-epigenesis, which is expected to avoid the afore- 

 said difficulties by assuming that vital phenomena are essentially the results of 

 intranuclear oscillating nervous discharges, and that the specific nervous cur- 

 rent deposits in the membrane centers a definite substance which, in turn, is 

 capable of again provoking the same specificity of current as that by which it 

 was deposited in a manner similar to that of electric accumulators. 



Appended is an essay reprinted from the Monist, July, 1911, on The Mnemonic 

 Origin and Nature of Effective Tendencies. By effective tendencies the author 

 means appetite, hungei', and other properties of the organism which tend to 

 keep it in a physiological equilibrium. 



Centro-epigenesis: Remarks on some problems of general embryology, 

 S. Becheb (Biol. Centbl., 29 (1909), Nos. 16, pp. 506-522; 17, pp. 523-5U; 18, 

 pp. 555-564). — ^A discussion of Rignano's hypothesis, noted above. 



The position of the question of the inheritance of acquired character?, 

 R. Semon (Der Stand der Frage nach der Vererbung erworbener Eigenschaften. 



