BY THE SAME AUTHOR 



A STUDY OF ANIMATE NATURE 



2 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 



IOLT AND COMPANY 



S NEW YORK 



