414 THE WORLD OF ANIMAL LIFE 



PROTOZOA 



This is a kingdom of very small creatures, which have in fact 

 only been revealed to us by the microscope, for they are all so 

 minute that they cannot be studied by the naked eye. Yet they 

 are as wonderful and as perfect as other living beings, and as well 

 adapted for the functions which they are destined to perform as 

 the Leviathan of the deep. 



