PART III. 



VARIOUS KINDS OF ANIMALS, AND 

 THEIR LIFE. 



CHAPTER IX. 



THE AMCEBA, HYDRA, AND OTHER SIMPLE 

 ANIMALS. 



Although the animals we know best are pretty large, 

 and the tiny midges which dance in swarms in the air, 

 and the little mosquito wrigglers which squirm in stag- 

 nant water seem to us among the smallest of animals, as 

 a matter of fact there are thousands of kinds much smaller 

 than the smallest we can see. Almost all of these minute 

 animals live either in fresh water or the ocean, and 

 among them are the simplest kinds in the entire animal 

 kingdom. Because they are too small to be seen by the 

 unaided eye they can be studied only with the compound 

 microscope. If the schoolroom is provided with one, 

 bring in a little water, together with a few small sticks or 

 decaying leaves, from the bottom of some stagnant pool, 

 and examine a drop or two of it under the microscope. 

 It will prove to be a tiny ocean world inhabited by mini- 

 ature animals and plants. In it will be found a few larger 

 animals preying on the smaller ones. There is sudden and 

 violent death here, and births, and locomotion and food- 

 getting and growth, and all the activities and functions of 



"3 



