X PREFACE. 



been placed at my disposal by the Society of Anti- 

 quaries, and the Eoyal Irish Academy. To Professor 

 Steenstrup, Dr. Keller, M. Morlot, and Professor 

 Kutimeyer, I am indebted for much information on 

 the subject of their respective investigations. Finally, 

 Mr. Busk, Mr. Evans, and Professor Tyndall have 

 had the great kindness to read many of my proofs, 

 and I am indebted to them for various valuable 

 suggestions. 



CHISELHTJRST, 



February, 1865. 



NOTE. In his celebrated work on the "Antiquity of Man," Sir 

 Charles Lyell has made much use of my earlier articles in the 

 " Natural History Review," frequently, indeed, extracting whole 

 sentences verbatim, or nearly so. But as he has in these cases 

 omitted to mention the source from which his quotations were 

 derived, my readers might naturally think that I had taken very 

 unjustifiable liberties with the work of the eminent geologist. A 

 reference to the respective dates will, however, protect me from any 

 such inference. The statement made by Sir Charles Lyell, in a 

 note to page 11 of his work, that my article on the Danish 

 Shell-mounds was published after his sheets were written, is an 

 inadvertence, regretted, I have reason to believe, as much by its 

 author as it is by me. 



