FOREWORD 



Even at the risk of beginning with an unnecessary remark, it may be 

 worth stating that this is not a text-book of cytology. The readers' 

 acquaintance with the elements of the subject has been assumed. The 

 intention of this book has been rather to review recent progress in the 

 study of the dividing cell, and to relate it where possible to the history 

 of the subject. It cannot be claimed that precisely equal justice is done 

 to all branches and in common with most cytological works, a larger 

 share of attention has been paid to those topics with which the re- 

 searches of the author have been concerned. The centre of gravity lies 

 more towards the physiological than to the descriptive aspects of the 

 subject, though the attempt has been made, however imperfectly, to 

 view the subject as a whole. In recent years there has been a marked 

 growth of interest in the dividing cell, though for several reasons it is 

 impossible yet to assess the extent of the permanent contributions to 

 knowledge which are now being made. One cannot forecast for how 

 long the present trends in research will be maintained, though their 

 momentum is still high. Caution in any estimates of this kind is sug- 

 gested by the previous reviews of this field, from which the contem- 

 porary reader may well have gained the impression that the way was 

 clear for substantial progress in promising directions, though not always 

 would such hopes have subsequently been fulfilled. For instance, in Pro- 

 fessor Faure-Frenoet's classical Cinetique du Developpement the approach is 

 from the standpoint of energetics, which has since been found more 

 applicable to the wider embryological aspects of growth than to the 

 study of the single cell in division. Again, Professor Gray's Experimental 

 Cytology, to which the writer in common with many others owe their 

 interest in the problems of the cell, has the unifying theme of cell 

 mechanics which is there expounded with masterly grace and pene- 

 tration. It is a sobering experience to realize how little the past twenty 

 years can add to the treatment of some topics on cell division to be 

 found in that book. There can be no doubt that the single living cell in 

 mitosis is one of the most difficult objects which the experimental 

 biologist has ever attempted to analyse. 



The present author has been fortunate in enlisting the help of two 

 colleagues, Dr Charity Waymouth and Dr Michael Swann, each with 

 special and indeed unique experience in their own fields ; their contribu- 

 tions appear on pages 163-182 and 1 19-134 respectively. He is further 

 indebted to them for the help which they have given in advice and 

 criticism elsewhere in the book, though their responsibility is here 

 entirely restricted to their own respective sections. 



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