SOME MINUTE ANIMAL 

 PARASITES 



OR 

 UNSEEN FOES IN THE ANIMAL WORLD 



CHAPTER I 



INTRODUCTION-THE CELL-PROTOPLASM 

 GENERAL CHARACTERS OF PROTOZOA 



THE world of Nature is a vast one, and the 

 range of living beings is of enormous extent. 

 Some of the most interesting organisms are those 

 that are so small that no eye can distinguish them 

 individually, and only when great magnification is 

 used can their form be described, though the effect 

 of masses of them may be only too obvious. The 

 animal world ranges from these tiny living units, 

 each independent, capable of carrying out every func- 

 tion associated with life, to the enormous aggregation 

 of living units, welded together into the vast complex 

 that is called an elephant or a man. In these latter 

 no one living unit is independent, but the units are 

 joined together in groups, each group having a 

 special function to carry out, and performing that 

 function mainly, and little else. 



What is a living unit ? Of what does it consist ? 

 If the simplest form of living animal be examined 

 under the microscope, it has the appearance of a 



