vi PREFACE. 



& Company for permission to reprint the 

 six articles which have appeared in the 

 " Popular Science Monthly." He is also 

 indebted for similar permission to the pub- 

 lishers of the "American Naturalist," "St. 

 Nicholas," "Recreation," and the "Riverside 

 Natural History," from each of which pub- 

 lications one article has been taken. 



LELAND STANFORD JR. UNIVERSITY, 



PALO ALTO, CAL., April 30, 1896. 



