vi PREFACE 



classes at the University of Neuchatel, He married a Swiss lady and 

 spent the rest of his life in that country, dying at Clarens, in March, 

 1927. According to Dr. A. E. Boycott, of London University, who 

 supplied the above facts, and has very kindly interested himself in 

 the recent editions of the Vade-Mecum, Bolles Lee towards the end 

 of his life became deeply engrossed in psychology and philosophical 

 reading. 



Between the recent editions and those of Bolles Lee there is this 

 difference — Lee tried every method himself, but in recent years the 

 subject has become so large, and the leisure of the collaborators and 

 editors so small, that this desirable attribute has not been attained 

 except in a few chapters. Several chapters in this book still stand 

 almost as Bolles Lee wrote them — e.g., those on invertebrate embryology 

 and nerve endings. 



The absence of Dr. Catcheside from England, and the fact that the 

 editors, living so far apart, have had to depend on the written word 

 for their collaboration, has made the editorship rather difficult, and 

 it is with great pleasure that the kindness and patience of the publishers 

 is acknowledged here. 



To avoid further delay, it was not possible to submit this preface to 

 the American co-editor. (This, however, gives the senior editor the 

 opportunity of saying how great is his debt to Dr. Theophilus Painter. 

 Not only has Professor Painter contributed a masterly article on animal 

 chromosome technique, but he has helped very considerably in other 

 parts of the book.) Both of us readily acknowledge the help we have 

 received from various British and American colleagues. Among these 

 must be mentioned Dr. E. A. Werner, Dr. K. C. Bailey and Dr. A. E. 

 Werner, of the Dublin L^niversity Chemistry Laboratory, and Mr. 

 Peter Gray, of the Edinburgh University Zoological Department. We 

 also thank Dr. R. H. Micks and Mr. L. E. Werner for their contribution 

 in the addendum. Finally, the index has been made by two Natural 

 Science graduates of Trinity College, Dublin, Miss Olive Aykroyd and 

 Miss Rosa Jones, whom we thank very cordially. 



J. BRONTE GATENBY, 



Trinity College, Dublin. 



THEOPHILUS PAINTER, 



Texas University, Austin, Texas. 



