X PBEFAGE 



Much of the manuscript of the chapter on Foods received 

 the careful criticism of the late Professor W. 0. Atwater. 

 Dr. William H. Park, Director of the Laboratories of the 

 New York Board of Health, and Dr. Thomas Spees Car- 

 rington. Secretary of the National Association for the Study 

 and Prevention of Tuberculosis, have given invaluable 

 assistance in the preparation of the chapter on microorgan- 

 isms. A considerable part of the " Human Biology '' was crit- 

 ically read by Dr. F. C. Waite of the Western Reserve Medical 

 School, by Mr. Harold E. Foster of the Enghsh Department 

 of the Morris High ^chool, and by the late Miss Martha F. 

 Goddard of the Morris High School, to whose memory these 

 volumes are dedicated. We wish, also, to express our hearty 

 appreciation of the generous permission of Henry Holt & Co. 

 to use some of the material published in Peabody's " Labora- 

 tory Exercises in Anatomy and Physiology." 

 ' Miss Mabelle Baker, a student in the Morris High School, 

 has contributed the drawings on which her initials appear. 

 To Mr. E. R. Sanborn of the New York Zoological Park, 

 and to Mr. A. E. Rueff of the Brooklyn Museum, we are 

 indebted for their skillful photography. The American 

 Museum of Natural History, the Brooklyn Museum, the 

 National Audubon Society, Doubleday, Page & Co., Dodd, 

 Mead & Co., Kny-Scheerer Co., Dr. C. F. Hodge of Clark 

 University, Dr. H. A. Kelly of Johns Hopkins Medical 

 School, Mr. C. W. Beebe of New York Zoological Park, and 

 others, have permitted us to make use of illustrative material. 



Cost prices for the items on the list of laboratory appa- 

 ratus and equipment were kindly furnished us by Bausch & 

 Lomb, Kny-Scheerer, and 0. T. Louis ; from these prices the 

 estimates on pp. 173 to 177 were prepared. 



October 31, 1912. 



J. E. P. 



A. E. H. 



