Preface ix 



worm-eaten. For the use of Plate XVIII, which appeared 

 in Leonardo da Vinci's Note-Books, I am under obligations 

 to the author, Mr Edward M c Curdy, M.A., and to Messrs 

 Duckworth & Co. Text-figs. 7, 18, yy, 78 and 112 are 

 reproduced by the courtesy of the Council of the Biblio- 

 graphical Society, from papers by the late Dr Payne, to 

 which the references will be found in Appendix II, while, 

 for the use of Text-fig. 108, I am indebted to the Royal 

 Numismatic Society. For permission to utilise the modern 

 facsimile of the famous Dioscorides manuscript of Juliana 

 Anicia, from which Plates I, II, and XV are derived, 

 I have to thank Prof. Dr Josef Ritter von Karabacek, of 

 the k. k. Hofbibliothek at Vienna. In connection with the 

 portraits of herbalists here reproduced, I wish to acknow- 

 ledge the generous assistance which I have received from 

 Sir Sidney Colvin, formerly Keeper of Prints and Drawings, 

 British Museum. 



I would also record my thanks to Mr A. W. Pollard, 

 Secretary of the Bibliographical Society, Prof. Killermann 

 of Regensburg, Signorina Adelaide Marchi of Florence, 

 Mr C. D. Sherborn of the British Museum (Natural 

 History) and Dr B. Daydon Jackson, General Secretary 

 of the Linnean Society, all of whom have kindly given me 

 information of great value. For help in the translation 

 of certain German and Latin texts, I am indebted to 

 Mr E. G. Tucker, B.A., Mr F. A. Scholfield, M.A., and 

 to my brother, Mr D. S. Robertson, M.A., Fellow of 

 Trinity College, Cambridge. 



I wish, further, to express my gratitude to my father 

 for advice and suggestions. Without his help, I should 

 scarcely have felt myself competent to discuss the subject 

 from the artistic standpoint. To my husband, also, I owe 

 many thanks for assistance in various directions, more par- 

 ticularly in criticising the manuscript, and in seeing the 

 volume through the press. I am indebted to my sister, 



