Preface ix 



through the great kindness of Messrs Sutton of Reading, 

 who have given me the privilege of watching such parts of 

 their work in raising varieties as seemed especially in- 

 structive, with unrestricted access to their pedigree books. 

 From this I have derived much profit, and many hints 

 which have formed the starting point for fuller experiment. 

 My hearty thanks are due to them for this important 

 assistance. 



W. BATESON. 



Grantchester, Cambridge. 

 February^ 1909. 



Note to the third impression, 



^ In the past^three years the progress of Mendelian 

 an^lysis^ has been very rapid, 5Jid certain chapters of this 

 bo ok, especia llyitho se dealing w ith_Caupling and JRepulsion^ 

 andjwithjije^Heredity of Sex, are_hr essential respects out - 

 J3f date. Kno wledge of these subjects is at present in a 

 transitional stage, and I have endeav^DuredJn a--series of 

 brief Appendixes to acquaint the reader with the nature 

 of the prijicipal advances made, while awaiting an oppor- 

 tunity_ ^fj:ewriting_the_book,____ 



I am obliged to Professor Arnold Lang and to 

 Mr C. C. Hurst for calling my attention to errors, which, 

 with some others, have been corrected. 



W. B. 



November^ 19 12. 



