INTRODUCTION 



THE following chapters contain, in simple lan- 

 guage, the main points of lectures delivered 

 to scientific societies, to colleges and upper-class 

 schools, and to large audiences in several parts of 

 England. As the lectures have influenced not a 

 few to form collections of suitable objects of natural 

 history, and also to purchase microscopes to enable 

 them to pursue their studies with success, I am 

 hopeful that the following chapters will lead a still 

 greater number to take up some department of 

 Nature as a definite study. This elementary intro- 

 duction to the microscopical side of creation is an 

 effort to persuade others to adopt a line of useful 

 reading and research, which must give to them much 

 pleasure. 



The occupation of spare moments in searching 

 for hidden beauties of Nature is both pleasant and 



