October 18, 1912] 



SCIENCE 



521 



condition of the subject. One could wish, 

 however, for a fuller analysis of the more im- 

 portant current theories. According to the 

 author, secondary sexual characters afford no 

 evidence fitted to solve the problems of sex. 

 The evidence of Mendelian inheritance of sex 

 is strongest in sex-limited inheritance; but 

 even here a non-Mendelian hypothesis is held 

 to be better. Sex-determination is a phe- 

 nomenon of cell physiology and cell regula- 

 tion. " To say more would certainly be pre- 

 mature." 



Several minor criticisms might be made. 

 Typographical errors are infrequent. " Bio- 

 type " is made synonymous with " pure line " 

 on page 122. One feels that the inheritance 

 of acquired characters could be discussed more 

 judicially after Mendelism, instead of before 

 it. On the whole, however, the book is very 

 well written and well made, and will be a val- 

 uable aid to both teachers and students. 



The Heredity of Richard Roe. By David 

 Starr Jordan. Boston, American Unitar- 

 ian Association. 1911. Pp. 165. Price, 

 $1.20. 



Heredity in the Light of Recent Research. 

 By L. DoNCASTER. Cambridge, The Uni- 

 versity Press. 1911. Pp. 143. Price, 40 

 cents. 



These two books are intended for the laity, 

 and are excellently designed for their pur- 

 pose. Richard Roe is a typical man, whose 

 history is described from germ cell to man- 

 hood. ■ The author's treatment of his hero is 

 conditioned by his public, and is popular to a 

 degree not usually combined with accuracy. 

 Because the book will be read by the uniniti- 

 ated, one feels that the case against prenatal 

 influences, for example, could have been made 

 stronger without compromising the author's 

 scientific standing. There is considerable 

 matter in the latter part of the volume that 

 seems at first sight irrelevant to the heredity 

 of Richard Roe. But the whole book is 

 written in such delightful style, a style which 

 those acquainted with the author will at once 

 recognize, that differences of opinion regard- 



ing emphasis or relevance are quickly for- 

 gotten. 



If Jordan's book furnishes inspiration, Don- 

 caster's supplies information. The latter vol- 

 ume gives, in small compass, the main facts 

 of heredity in a form readily grasped by any 

 intelligent reader, yet with all the accuracy 

 which the author's scientific reputation leads 

 one to expect. Heredity is approached by the 

 usual road, with a discussion of variation, its 

 causes, and its study by statistical methods. 

 The reader is given an elementary under- 

 standing of Mendelism, and is led within 

 sight of some of the disputed questions re- 

 garding purity of gametes, inheritance of ac- 

 quired characters, etc. Heredity in man, 

 with its sociological bearing, closes the main 

 part of the volume. Two appendices treat of 

 the history of theories of heredity and the 

 material basis of heredity. There is a short 

 glossary, and a bibliography in which those 

 books suitable for general readers are spe- 

 cially designated. 



A. Franklin Shull 



University of Michigan 



A CLASSIFICATION OF THE DEPART- 

 MENTS OF BOTANY AND AN 

 ABBANGEMENT OF MATERIAL 

 BASED TEEBEON 



No one has made a serious attempt at the 

 classification of the departments of botany. 

 Various short classifications have been given 

 in text-books with a view to arranging the 

 facts presented to botanic students, but I am 

 not aware that these have been made with a 

 thought at presenting in logical sequence the 

 divisions into which botany naturally may be 

 divided. Such an arrangement is an impor- 

 tant matter when the botanist wishes to ar- 

 range his books, photographs, microscopic and 

 lantern slides, as well as museum material of 

 plants. Recognizing the lack of such infor- 

 mation, the attempt is made here to give a 

 logical classification of the departments of 

 botany, and it is hoped that the readers of 

 Science will make additions and corrections, 

 or suggest a rearrangement of this preliminary 



