FOREWORD 



He is further indebted for much advice and assistance to Dr Honor 

 Fell, Dr Michael Webb, and other colleagues at the Strangeways 

 Laboratory; to Dr Gray and to Dr Pelc of the M.R.G. Radio- 

 therapeutical Research Unit, to Dr C. D. Darlington and his 

 colleagues at the John Innes Horticultural Institution, to Dr R. A. 

 Beatty of the Department of Animal Genetics, Edinburgh, and to 

 Dr Ivor Cornman of Washington who generously allowed him to make 

 use of his unpublished survey of the effects of aromatic compounds on 

 dividing cells, and to his publishers for their interest in this book and 

 their promptitude in its publication. 



Cambridge, October, 1951 



'Les methodes nouvelles de I'anatomie microscopique qui per- 

 mettent de saisir la matiere vivante aux differentes periodes de son 

 evolution, de la fixer dans sa forme, de differencier, au moyen de 

 reactifs chimiques, les elements qui entrent dans sa constitution, les 

 perfectionnements apportes aux objectifs des microscopes qui font 

 apercevoir des details qui devaient fatalement echapper aux anciens 

 observateurs, ont montre que la structure et la vie d'une cellule sont 

 plus complexes qu'on ne le pensait. Nous sommes loin aujourd'hui du 

 temps ou Ton considerait la cellule comme une petite masse de sub- 

 stance homogene, sarcode ou protoplasma, entouree ou non d'une 

 membrane d'enveloppe et renfermant un petit corps refringent, le 

 noyau, contenant lui-meme un corps plus petit, le nucleole.' 



L, F. Henneguy, 1896. 



'From the extensive investigations on the mechanism of cell division 

 it must be concluded that there is as yet no full understanding of the 

 physical and chemical mechanisms which bring forth this process.' 



E. S. G. Barron, 1949. 



* We have learned many things about cell division, but we do not 

 know much in the end.' 



W. D'Argy Wentworth Thompson, 1942. 



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