PREFACE. 



n^HIS volume is made up of a number 

 ^ of unconnected sketches and addresses, 

 coming more or less distinctly under the 

 head of Popular Science. Three of them 

 — the paper on " The Dispersion of Fresh- 

 Water Fishes," the address on " Darwin," 

 and the paper on " The Evolution of the 

 College Curriculum" — are here published 

 for the first time. The others have appeared 

 in various periodicals. All the articles have 

 been freely retouched, and some of them en- 

 tirely rewritten. The author wishes to express 

 his obligations to Messrs. D. Appleton & Co., 

 to S. E- Cassino & Co., and to the Century 

 Company for permission to reprint articles 

 which have appeared in the " Popular Science 

 Monthly," in the "Standard Natural History," 

 and in " St. Nicholas." 



D. S. J. 



University of Indiana, 



Bloomington, August, 18S7. 



