Descendenz u. Hybriden. 265 



iied by Karl Pearson; II. the Mendelian Hypothesis; and 

 III. the Theory of Alternative Inheritance, which divides the 

 offspring into tvvo groups more intimately associated with one 

 or the other parent. 



The curve for Ancestral Heredity is a horizontal straight 

 line; for Mendel's Theory it is a parabola with axis along the 

 axis of parental character; and for Alternative Inheritance it is 

 a hyperbola with its real axis parallel to the axis of parental 

 character. 



The authors own measurements of stature, span, fore-arm, 

 and cephalic index in man lead to the conclusion that within 

 the limits of probable error of random sampling, the curve is a 

 horizontal straight line. Hence he concludes that of the three 

 theories, that of Ancestral Heredity most nearly approaches the 

 truth. E. Drabble (London). 



Pearson, Karl, On Homotyposis in Homologous but 

 Diffe rentiated Organs. (Proc. Royal Soc. London. 

 March 1903.) 



In the foregoing abstract the influence of age and position 

 on homotyposis was noted. In the memoir under consideration 

 the author points out that as soon as we can correlate 

 between the age and the quantitative character of the homo- 

 logous organs, Situation on the orgauism and this character, 

 and local environment and this character, we can allow 

 for the difierentiation of homologous parts or reduce them 

 to pure homotypes. The methods of finding the corrections to 

 be made to the apparent homotypic correlation when the pairs 

 of homologous parts are differentiated from each other by their 

 periods of growth and by their Situation on the organism 

 are described. E. Drabble (London). 



TraCY, W. W„ The Influence of Climate and Soils on 

 the Transmitting Power ofSeeds. (Science. Vol. XIX. 

 May 6, 1904. p. 738—740.) 



Concerned with certain cultivated plants. Thinks that soil 

 has a cumulative effect wich is „carried" in the seed, in the 

 case of leguminous plants, while climate does not affect them. 

 Also mentions other forms which are not affected by soil, but 

 are by climate. H. M. Richards (New York). 



Vernon, H. M., Variation in Plants and An im als. IX, 

 415 pp. Holt & Co. New York 1903. 



The book is divided into three parts: I The facts of 

 Variation, II The causes of Variation, III Variation in its relation 

 to evolution. While the subject matter concerns animals more 

 than it does plants, frequent reference is made to the latter. 

 The first chapter deals with the measurement of Variation. In 

 the second chapter, on dimorphism and discontinuous Variation, 



