vi PREFACE 



many and vast changes. Some of these have there- 

 fore been indicated in a tentative way. Like other 

 previous hypothetical maps they will be objected to 

 by the timid, on principle ; critics with more expert 

 knowledge will amend them. Meanwhile, may the 

 reader not forget that he has embarked in a frail 

 craft upon a romantic voyage across unknown seas 

 in search of undiscovered lands. 



Herewith ends the general part, the principles 

 of distribution. The special part deals with the 

 distribution of a considerable number of various 

 groups of animals, mostly terrestrial vertebrates, 

 selected for their fitness as test cases. Some seem 

 to tell their story well ; others, owing to remote age, 

 insufficient data, and want of fossils, have got their 

 record into a tangle. In a few sample cases, for 

 instance the marsupials, an attempt has been made 

 to unravel such a tangle, and to spin a coherent yarn. 

 Since this cannot be done without recourse to many 

 technical terms and names, it makes rather stiff read- 

 ing. Such technicalities are the bane of the general 

 reader be he never so interested in the subject, but 

 where homely words and names are wanting, he has 

 to put up with them. Further, he should know the 

 geological time-table as well as his geography. 



H. dr. 



February, 1913. 



