EDITORIAL STATEMENT. 



Seven manuscripts becaring on the suliject of this volume, nearly 2,000 pages 

 of breeding record, and about 200 illustrations with accompanying legends com- 

 prised the material from which the present volume is assembled. 



The first of these manuscripts was written in 1897. It treats of inheritance as 

 limited by sex, and is placed in Chapter XII. Two lectures in 1898 supplied the 

 materials for Chapter XVI and for a fragment of Chapter XL The third manu- 

 script dates from about 1904, and was slightly revised later. It is the most general 

 and comprehensive treatment of the series and is here made to serve as an intro- 

 ductory chapter. Some tabulations or lists which accompanied this paper have, 

 however, been separated from it and expanded to include studies made after 1904. 

 These expansions treat partly of some crosses made earlier than 1904 but not 

 adequately summarized at that time, and partly of crosses made later by the 

 author and summarized wholly by the editor. These completed summaries now 

 appear as Chapter II. The fourth manuscript, "On the Divisibility of Charac- 

 ters," was written in 1906 and is the basis of Chapter XVII. The fifth, dated 1907 

 and entitled "Heredity," touches the broader aspects of development and becomes 

 the first section of the concluding statement of Chapter XIV. To this state- 

 ment have been added three or four pages on " Mendelian Heredity" from a lecture 

 in 1908 and some other materials from the papers next to be mentioned, which 

 have also found their natural place in the same chapter. 



A seventh and very incomplete manuscript (R 16, WW 1), consisting largely 

 of short summaries and conclusions drawn chiefly from later studies, was written 

 in 1909 and 1910. The conclusions found here, though disconnectedly set down in 

 about 30 small pages, re])resent Professor Whitman's most mature and final judg- 

 ment in regard to his work with the dominance of sex and color, with its control, 

 and with the dependence of this result upon relative "fertihty" and "strength" 

 of the germ-cells. 



The major task of the editor has been the summarizing of the data on v.hich 

 these conclusions from the work of the author's later years were based and their 

 tabulation and presentation. In most cases this has meant the tabulation of data 

 concerning breeding, quotation from the specific record where possible, and from 

 the notes of the seventh manuscript till this was fully presented; and, finally, 

 undertaking such analysis and discussion as seems absolutely necessary to render it 

 available to students. But such analysis and discu.ssion by the editor have perhaps 

 not been unduly pressed; indeed, the editor believes that, although he has worked 

 much, the reader has yet something to do to avail himself of all that lies in the 

 volume. The results of this effort to present fully these materials may be found 

 chiefly in Chapters II to XIV inclusive. The elaborateness of the detailed tabulations 

 in those chapters — unusual as this method of presentation is — will be found quite 

 necessary because of the nature of the problems treated. For this reason, too, it 

 was deemed advantageous greath^ to amplif\' from the numerous later records the 

 relatively few summaries made by the author and to add manj^ unsummarized 

 earlier records as well. 



