BY THE SAME AUTHOR 



A STUDY OF ANIMATE NATURE 

 a volumes 



THE SECRETS OF ANIMAL LIFE 

 THE WONDER OF LIFE 

 THE BIOLOGY OF THE SEASONS 

 DARWINISM AND HUMAN LIFE 



New Edition 



INTRODUCTION TO SCIENCE 

 Volume 21 in the 

 Home University Library 



HENRY HOLT AND COMPANY 



PUBLISHERS NEW YORK 



