E-text prepared by Paul Hollander, Malcolm Farmer, Keith Edkins, and the Project Gutenberg Online Distributed Proofreading Team (http://www.pgdp.net) Note: Project Gutenberg also has an HTML version of this file which includes the original illustrations. See 28775-h.htm or 28775-h.zip: (https://www.gutenberg.org/cache/epub/28775/pg28775-images.html) or (https://www.gutenberg.org/files/28775/28775-h.zip) Transcriber's note: A few typographical errors have been corrected: they are listed at the end of the text. Fig. 8 has been re-mastered to match the text (the Black boxes were shown as Albino and the heterozygous Albinos as Black). Superscripted numbers are indicated by a carat character followed by the superscript. For example, 2^4 denotes 2 raised to the fourth power and 2^(10) denotes 2 raised to the tenth power. Subscripted numbers are indicated by an underscore followed by the subscript. For example, in the expression "F_1" the 1 is a subscript. Page numbers in this text file are enclosed in curly brackets. This enables the reader to use the index by searching for the page number. To find page 35, search for {35}. [Illustration] MENDELISM by R. C. PUNNETT Fellow of Gonville and Caius College Professor of Biology in the University Of Cambridge THIRD EDITION Entirely Rewritten and Much Enlarged New York The MacMillan Company 1911 All rights reserved Copyright, 1911, by The MacMillan Company. Set up and electrotyped. Published May, 1911. Norwood Press J. S. Cushing Co.--Berwick & Smith Co. Norwood, Mass., U.S.A. {v} PREFACE A few years ago I published a short sketch of Mendel's discovery in heredity, and of some of the recent experiments which had arisen from it. Since then progress in these studies has been rapid, and the present account, though bearing the same title, has been completely rewritten. A number of illustrations have been added, and here I may acknowledge my indebtedness to Miss Wheldale for the two coloured plates of sweet peas, to the Hon. Walter Rothschild for the butterflies figured on Plate VI., to Professor Wood for photographs of sheep, and to Dr. Drinkwater for the figures of human hands. To my former publishers also, Messrs. Bowes and Bowes, I wish to express my thanks for the courtesy with which they acquiesced in my desire that the present edition should be published elsewhere.