LIBRARY 



PREFACE 



/Vn accident in 1905, and the nature of my official occupation, 

 forced me to work that could be done in spare time with the 

 aid of a pen and a library, and since then I have largely devoted 

 myself to the study of geographical distribution. The dictionary 

 for which I was responsible emphasised in my mind the enormous 

 variety in sizes and distribution of families, genera, and species. 

 All seemed a nearly hopeless confusion. Yet this is not nature's 

 way; her work is always beautifully planned, as Darwin had 

 already shown in the wonderful theory of evolution, whose 

 establishment as a working guide through the intricacies of life 

 was due to him, and gave hiin his lasting claim to fame. Without 

 a mechanism to operate it, however, few were prepared to make 

 so great a break with what had gone before. In natural selection, 

 Darwin produced an apparently serviceable mechanism, which 

 was so familiar to every one that it had a great appeal, soon 

 resulting in the establishment of evolution in an unassailable 

 position. But during the last fifty years there has always been 

 an underlying feeling that all was not well -sWth natural selection. 

 The writer, though brought up in its strictest school, soon began 

 to feel very doubtful about it, and a few years of experience with 

 tropical vegetation made him realise that selection could not be 

 responsible for evolution. From that time onwards he has never 

 ceased to bring up objections to it, though rarely has any answer 

 to these been attempted. Selection is now no longer required as 

 a support for evolution, and must take its proper place, which is 

 one of great importance, as has been pointed out here and 

 elsewhere. 



The writer then set out, some thirty-five years ago, to find 

 some definite laws underlying the welter of facts in distribution. 

 The first thing that really set him upon the track was the 

 discovery in 1912 of the "hollow curve" formed by the numbers 

 of species in the genera of the Ceylon flora, a curve which soon 

 proved to be universal in both floras and faunas. This led to the 

 development of the theory set out in Age and Area in 1922. 

 Being, among other things, a flat contradiction of the theory of 

 gradual adaptation through the agency of natural selection, this 

 theory of age and area was not accepted, but as the counter 



