PREFATORY NOTE 



THIS book of mine has little need of preface, for indeed it is 

 "all preface" from beginning to end. I have written it as 

 an easy introduction to the study of organic Form, by methods 

 which are the common-places of physical science, which are by 

 no means novel in their application to natural history, but which 

 nevertheless naturalists are little accustomed to employ. 



It is not the biologist with an inkling of mathematics, but 

 the skilled and learned mathematician who must ultimately deal 

 with such problems as are sketched and adumbrated here. I pretend 

 to no mathematical skill, but I have made what use I could of 

 what tools I had; I have dealt with simple cases, and the mathe- 

 matical methods which I have introduced are of the easiest and 

 simplest kind. Elementary as they are, my book has not been 

 written without the help — the indispensable help^ — of many friends. 

 Like Mr Pope translating Homer, when I felt myself deficient I 

 sought assistance! And the experience which Johnson attributed 

 to Pope has been mine also, that men of learning did not refuse 

 to help me. 



I wrote this book in wartime, and its revision has employed 

 me during another war. It gave me solace and occupation, when 

 service was debarred me by my years. 



Few are left of the friends who helped me write it, but I do not 

 forget the debt I owe them all. Let me add another to these 

 kindly names, that of Dr G. T. Bennett, of Emmanuel College, 

 Cambridge; he has never wearied of collaboration with me, and 

 his criticisms have been an education to receive. 



D. W. T. 

 1916-1941. 



