viii PREFACE 



graphs of insects; to Dr. L. O. Howard, U. S. Entomol- 

 ogist, for electros of figs. 45, 52, 56, 68, 81, 82, 83, 

 84, 87, 90, and 92 ; to Professor L. L. Dyche, University 

 of Kansas, for photographs of his mounted groups of 

 mammals; to Mrs. Elizabeth Grinnell, Pasadena, Calif., 

 for photographs of birds; to Mr. J. O. Snyder, Stanford 

 University, for photographs of snakes; to Mr. Frank 

 Chapman, editor of " Bird-lore," for electros of photo- 

 graphs of birds; to Mr. G. O. Shields, editor of " Recrea- 

 tion," for an electro of the photograph of a bird; to the 

 American Society of Civil Engineers for electros of photo- 

 graphs of boring marine worms; to Cassell & Co., for 

 electros of three photographs from nature; to Geo. A. 

 Clark, secretary Fur Seal Commission for photographs of 

 seals; and to the Whitaker and Ray Co., San Francisco, 

 for electros of figs. 46, 59, 60, 61, 64, 65, 93, 94, 97, 98, 

 99, 100, 1 02, 119, and 166 to 172, published originally in 

 Jenkins & Kellogg's " Lessons in Nature Study." The 

 origin of each of these pictures is specifically indicated in 

 connection with its use in the book. 



The author's sincere thanks are also due to Mrs. David 

 Starr Jordan and to Mr. J. C. Brown, graduate student in 

 zoology in Stanford University, for their assistance in the 

 correction of the MS., and in the preparation of the lab- 

 oratory exercises respectively. The chapters of Part II 

 relating to the vertebrates were read in MS. by President 

 David Starr Jordan, whose aid and courtesy are gratefully 

 acknowledged. Similar acknowledgments are due Pro- 

 fessors Harold Heath and R. E. Snodgrass for read- 

 ing the proofs of the directions for the laboratory ex- 

 ercises. 



VERNON LYMAN KELLOGG. 



STANFORD UNIVERSITY, May, 1901. 



