Transcriber’s notes: The text of this e-book has mostly been preserved in its original form. One spelling error was corrected (considertion → consideration) and a few missing full stops inserted, but inconsistent hyphenation was left unchanged. Italic text is denoted by _underscores_. Superscripted text is indicated by a preceding caret mark, e.g. 2^{n} and subscripted text by a downward arrow, e.g. A↓{2}. Footnotes have been numbered and positioned below the relevant paragraphs. MENDEL’S PRINCIPLES OF HEREDITY London: C. J. CLAY AND SONS, CAMBRIDGE UNIVERSITY PRESS WAREHOUSE, AVE MARIA LANE, AND H. K. LEWIS, 136, GOWER STREET, W.C. [Illustration] Glasgow: 50, WELLINGTON STREET. Leipzig: F. A. BROCKHAUS. New York: THE MACMILLAN COMPANY. Bombay and Calcutta: MACMILLAN AND CO., LTD. [_All Rights reserved._] [Illustration: GREGOR MENDEL Abbot of Brünn Born 1822. Died 1884. _From a photograph kindly supplied by the Very Rev. Dr Janeischek, the present Abbot._] MENDEL’S PRINCIPLES OF HEREDITY A DEFENCE BY W. BATESON, M.A., F.R.S. _WITH A TRANSLATION OF MENDEL’S ORIGINAL PAPERS ON HYBRIDISATION._ CAMBRIDGE: AT THE UNIVERSITY PRESS. 1902 Cambridge: PRINTED BY J. AND C. F. CLAY, AT THE UNIVERSITY PRESS. PREFACE. In the Study of Evolution progress had well-nigh stopped. The more vigorous, perhaps also the more prudent, had left this field of science to labour in others where the harvest is less precarious or the yield more immediate. Of those who remained some still struggled to push towards truth through the jungle of phenomena: most were content supinely to rest on the great clearing Darwin made long since. Such was our state when two years ago it was suddenly discovered that an unknown man, Gregor Johann Mendel, had, alone, and unheeded, broken off from the rest--in the moment that Darwin was at work--and cut a way through. This is no mere metaphor, it is simple fact. Each of us who now looks at his own patch of work sees Mendel’s clue running through it: whither that clue will lead, we dare not yet surmise. It was a moment of rejoicing, and they who had heard the news hastened to spread them and take the instant way. In this work I am proud to have borne my little part.