INTRODUCTION 9 



the whole, as are the translations of these works by which the Clarendon 

 Press has enriched English scientific literature, it is the original work 

 rather than the translation that we have in all cases followed. We wish 

 here to express the great obligation under which we lie to these writers, 

 and to acknowledge the extent to which we have borrowed from them. 

 In the chapter on Fossil Vascular Cryptogams we have, to a considerable 

 extent, followed Graf zu Solms-Laubach's excellent ' Einleitung in die 

 Palaeophytologie,' though with some modifications. To the description of 

 each group or family we have appended a bibliography of the researches 

 on which that description is founded ; these having again been consulted, 

 wherever possible, in the original language. 



