PREFACE 



THOUGH the importance of Physiology in secondary schools 

 is everywhere recognized, little attempt has been made to 

 place the subject on an experimental basis. This book has 

 been prepared in an effort to call attention to the great field 

 which this subject presents for laboratory study. 



The starred topics in the following table of contents con- 

 stitute a brief course covering that which is essential; and 

 the optional exercises make it possible to extend the work at 

 the discretion of the teacher. 1 The ingenuity of the teacher 

 will readily suggest substitutes for the material suggested when 

 the laboratory facilities of the school are inadequate. 



Some of the exercises may be made demonstrations, and 

 time in school may also be saved by assigning some of the 

 simpler exercises as part of the home work of the pupil. 



I wish to acknowledge the many helpful suggestions given 

 me by my colleagues of the High School of Commerce and 

 by members of the Columbia University faculty. I have 

 also found many useful suggestions in the works of Messrs. 

 Foster and Langley, J. E. Peabody, M. L. Macy, H. Newell 

 Martin, Hammarsten, Verworn, Wilson, and Schafer. 



I wish also to express my great indebtedness to Dr. E. A. 

 Darling of Harvard College and to Mr. Frank O. Payne of 

 the High School of Commerce for their critical review of the 

 manuscript and for the aid they have given me in its prepara- 

 tion; and to my wife for great assistance in the many details 

 of grammatical arrangement and mechanical labor involved 

 in the work. W H E 



THE HIGH SCHOOL OF COMMERCE, 

 NEW YORK CITY. 



1 The book in its starred topics meets the requirements of the New York 

 State Syllabus, and as a whole has been accepted by the Harvard College 

 authorities as meeting the entrance requirements of that institution. 



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