AUTHOR'S PREFACE. 



THIS book is the child of necessity, and was made 

 to serve instead of a personal reply to the inquiries 

 concerning the Agassiz Association, which came more 

 rapidly than pen could answer them. For about two 

 years a list of all such questions was carefully kept, 

 and then the answers were written here as concisely 

 and accurately as possible. As the Association has 

 grown the questions have increased in number and 

 scope, so that with each new edition comes the neces- 

 sity for an enlargement and revision of the book. 

 The author has been so greatly assisted in its prepa- 

 ration and revision that he is now little more than 

 its grateful editor, who begs to return his thanks to 

 those whose kindness has contributed so essentially to 

 the value of the book. Professor Hyatt has honored 

 our work to the verge of flattery in his whole-hearted 

 introduction. To Professors W. W. Bailey, of Provi- 

 dence, R. I. ; T. H. McBride, of Iowa City, la., and 

 William B Werthner, of Dayton, O., our readers are 

 indebted for the valuable suggestions in botanical 

 work. Professor W. O. Crosby has revised the chap- 

 ter on the study of minerals. The Manhattan Chapter 

 of the Agassiz Association has given assistance with 

 regard to taxidermy. The List of Books could not 

 have been properly prepared but for the co-operation 

 of Professors' McBride, Crosby, Stokes and Clarke ; 

 Geo. Bird Grinnell, Ph.D. ; S. P. Sharpies, State 

 Assayer ; Hilborne T. Cresson, and, particularly, Mr. 

 O. Bjerregaard, of the Astor Library, and Dr. W. H. 

 Seaman, who have diligently revised the entire list. 



