VI PREFACE 



which could be extended to many other animals, using only informa- 

 tion that already exists in great quantity. It is my hope that others may 

 thus be encouraged to undertake such work, which in my view could 

 lead to new discoveries, obtained direct from field data. 



When I came to consider what acknowledgements I should make to 

 those who have helped in the production of the results and of this book, 

 I was oppressed by the debt I owed to so many. The references give 

 an insufficient indication of this, for I have only included those that 

 bear directly on the matter under discussion, and I must have omitted 

 many that could have been mentioned. I therefore decided to confme 

 myself to actions of particular value to one who, hke myself, works 

 on this subject in isolation as a recreation. It is always necessary to 

 spend a good deal of time in libraries, but the pleasant custom of 

 exchanging reprints with other herpetologists has led over the years 

 to a collection that I have been able to study whenever I felt inclined, 

 at home. To those who have sent me reprints, I should like to say how 

 useful these have been. 



Finally, I must pay a tribute to Dr. W. H. Parker, until recently 

 Keeper of Zoology at the British Museum (Natural History). As a 

 young man returning with some Bombina variegata from a hoHday in 

 France, and having made some observations on these animals, I was 

 directly encouraged by a young Assistant Keeper in the Reptile 

 department to publish the results, and to go on and do more. Dr. 

 Parker is a taxonomist, and I, as a student of one or a few animals, had 

 little need of taxonomic assistance, so that there might seem to be 

 httle direct connexion between this book and Dr. Parker's work, but 

 that is, in fact, how it all began, for Dr. Parker was the young Assistant 

 Keeper. 



