THE PURPOSE AND PLAN OF THIS BOOK 



The aim of this book is to correlate the allied subjects of botany, 

 zoology, and human physiology in a general course of biology for the 

 first year of the high school. The foundation principles upon which 

 this correlation is made are that the life processes of plants and of 

 animals are similar, and in many respects, identical ; that the prop- 

 erties and activities of protoplasm are the same whether in the cell 

 of a plant or of an animal ; and that the human body is a delicate 

 machine built out of that same mysterious living matter, protoplasm. 

 With such a foundation correlation is not only possible, but natural. 



The following pages are the results of my experience with large 

 classes of young students in the first year of the high school. The 

 average age of such pupils is about fourteen years. To such pupils 

 the life activities of plants and animals have an appealing interest ; 

 simple experiments in plant physiology are performed with never 

 failing zest. Laboratory and field work, so far as they relate to 

 adaptations to functions, are readily comprehended. 



For young students laboratory questions should be simple and 

 few ; they should apply to structures easily found, and deal with ex- 

 ternals only. Minute directions are necessary in order to insure the 

 successful working out of the given problem. The form of the lab- 

 oratory questions must, after all, be left to the individual teacher. 

 The paragraphs on laboratory work which follow are suggestions. 

 Eor formal directions in botany and zoology according to the note 

 and question method, the reader is referred to Hunter and Valentine, 

 Laboratory Manual of Biology, Henry Holt and Company. For lab- 

 oratory exercises in human anatomy and physiology, Eddy, Expert- 



