1. PREFATORY REMARKS 



tween us in regard to these posthumous volumes should be 

 open and above board. Where the opinions of the present 

 time differ from those of a few years ago, I wish that the 

 grounds of this change should be apparent, in order that the 

 reader may in all cases judge for himself. 



There are now appended to this work two papers, in the 

 form of addresses to Societies, — the Royal Physical of Edin- 

 burgh, and the British Association, — which contain remarks 

 of a more recent date than the " Foot-prints," upon the struc- 

 ture of the ancient ganoids. They seem to have been in 

 some sort supplementary to the " Foot-prints," and would 

 no doubt have been embodied in the new edition which the 

 author contemplated. I was not aware of the existence of 

 these papers until Sir Philip Egerton, in preparing his notes 

 on the fishes of the Old Red, made inquiries whether Hugh 

 Miller had left any other details on the subject than were 

 to be found in his published writings. Search was made 

 among certain old repositories, and these lectures found, 

 which, it is hoped, will prove of great interest and of some 

 value to geologists, and to those who like to follow the 

 science into its minuter details. Some repetitions may per- 

 haps be involved ; but the reader will excuse these, as it is 

 impossible altogether to avoid them without destroying the 

 unity of the addresses. Sir Philip Egerton thus expresses 

 himself regarding them : — " I have read carefully and with 

 great interest the manuscripts you have sent me. That on the 

 structure and relations of the earlier ganoids seems to have 

 been read before some Society. It is a paper of great inte- 

 rest^ and would be a most valuable and interesting addition 

 to the reprint of the " Foot-prints." You will find a passage 



