PREFACE. " vii 



fascinating, and deserving of more attention than it has of late 

 years received. But Mr. "Wallace's important and interesting 

 work {Island Life), which has just appeared while I pen these 

 lines, will doubtless give a fresh impulse to the study among 

 naturalists, and should the present volume assist in the same 

 direction, I shall feel well repaid for my labour. 



The reader will not, I hope, have any difficulty in under- 

 standing the precise signification I attach to such terms as 

 "Prehistoric," "Pleistocene," " Preglacial," "Glacial," "Inter- 

 glacial," " Postglacial," etc. But it may be as well to state here 

 that I employ the term "Prehistoric" in the same extended 

 sense as Professor D. Wilson, by whom "it was purposely 

 coined to express the whole period disclosed to us by means 

 of archaeological evidence, as distinguished from what is known 

 through written records." In the classification adopted by me, 

 " Pleistocene " or " Quaternary " includes the Preglacial, Glacial, 

 and Interglacial deposits ; while " Postglacial " is restricted to 

 those accumulations which belong to a later date than the last 

 great extension of glacier-ice in Europe — a sense in which it 

 has long been employed in Scotland, Scandinavia, Switzerland, 

 and the Continent generally. This differs somewhat from the 

 classification advanced by certain English geologists, who would 

 include under the term "Postglacial" many accumulations of 

 Pleistocene age, which it is the object of these pages to show 

 are of Interglacial, and not Postglacial, date. 



To the many friends and correspondents at home and abroad, 

 who have kindly satisfied my inquiries and favoured me with 

 copies of their papers, I would here express my grateful thanks. 

 I have also to acknowledge my indebtedness to Dr. J. Evans, 

 who has courteously allowed me to copy from his great work on 

 Ancient Stone Implements the illustrations which are given in 

 Plate C. And to Professor T. Eupert Jones similar acknow- 



