AUTHOR'S PREFACE 



To THIRD EDITION. 



This book is the child of necessity, and was made 

 to serve instead of a personal reply to the inquiries con- 

 cerning 1 the Agassiz Association, which came more rapid- 

 ly 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 accurate- 

 ly as possible. As the Association has grown the ques- 

 tions have increased in number and scope, so that with 

 eacih new edition comes the necessity for an enlargement 

 and revision 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 Providence, 

 K. 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. 

 has revised the chapter 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, 

 w T ho have diligently revised the entire list. Other assist- 

 ance is acknowledged in the text, and if among so many 

 helpers any have failed of mention, it is not for lack of 

 appreciation, but because the book is now in press and 

 cannot be consulted. Finally, the author wishes to ex- 

 press his gratitude to the publishers for their hearty 

 interest and most kind and courteous consideration. 



Pittsfield, Mass., Jan. 14, 1888. 



