THE ANIMAL KINGDOM. 



15 



hausted by the performance of the functions of vegetable 

 life, sleeps at the close of day ; the animalcule, notwith- 

 standing its prodigious activity, does not. 



Struck with the fact, Owen has conjectured that this ex- 

 traordinary activity might be due to the enormous develop- 

 ment of the digestive system in the Infusoria, seeing that 

 a man, a lion, or a tiger has only one stomach, an ox .or a 

 camel four or five, whilst invisible Microzoa have sometimes 

 a hundred ! 



4. Infusoria procured by Sir James Ross from the bottom of the Antarctic Ocean, as seen with 



the microscope. 



In proportion as science has been perfected the horizon 

 of life has been enlarged, and a microscopic world, full of 

 animated existence, has been revealed in every spot to 

 which investigation has been able to reach. The Polar ices, 

 the elevated regions of the atmosphere, and the gloomy 



