PREFACE. XXIX 



But the cause must here be sought in the pre- 

 vious obscurity of the subject, in the novelty of the 

 views, and in the necessity thence arising for an 

 ample elucidation. Hereafter, should these views 

 be received as correct, and become an established 

 part of geological belief, these details will admit 

 of condensation . Where the facts have been such 

 as are generally received, they are stated in the 

 most brief form which was consistent with the 

 objects in question . The same apology will apply 

 to those repetitions of the same matter in differ- 

 ent lights, which will occasionally be found 

 throughout the work. From the same cause 

 arose explanations and reasons, in defence of par- 

 ticular statements, and in justification of the 

 adopted arrangements. To have rescinded that 

 justificatory matter, which is in itself too often 

 tedious and inconvenient, would have been to 

 incur the greater blame of dogmatic assertion, and 

 of an attempt to support by mere opinion, or from 

 caprice, that which appeared really founded on a 

 fair induction of evidence, or on some conveni- 

 ence in the plan of the work. It is bare justice 

 to a reader to assign reasons for that novelty 



