Viii THE MOLECULAR ARCHITECTURE OF PLANT CELL WALLS 



Division, C.S.I.R.O., Melbourne, Australia. In particular I would say 

 that I have not hesitated to express opinions on controversial points 

 and I hope they will forgive me if I have taken undue liberties. The 

 inclusion of a good deal of hitherto unpublished material has possibly 

 led me into statements which may eventually need to be modified: but 

 again I have preferred to liven the book at the risk of some later correc- 

 tions rather than adhere rigidly to fully established interpretations. 



I am deeply indebted to Mrs. F. R. Langstadt for the very able way 

 in which she has converted my almost illegible pages into typescript, 

 and to Mr. B. Clarke for the preparation of many of the prints with 

 which the book is illustrated and in particular for the colour plate 

 (Plate III). To Dr. M. F. E. Nicolai, Dr. L. C. Spark and Miss L. I. 

 Scott I am grateful for assistance in proof-reading; any errors which 

 remain are my own responsibility. 



It has been my privilege during my research life to be in close 

 association with some of the leading authorities in various fields of 

 science. To all of them, and particularly to Professor W. T. Astbury 

 and, of late years, to Professor I. Manton, I owe a debt I can never 

 repay. It is my sorrow and misfortune that I can no longer convey an 

 expression of my gratitude to the one to whom I owe the most — the 

 late Professor J. H. Priestley. 



R. D. P. 



Department of Botany, 

 University of Leeds. 



