PAET II. 



CHAPTER I. 



PROTOZOA RHIZOPODA HISTORY OF INFUSORIAL ANIMALCULES 



MONADS FOSSIL INFUSORIA, ROTIFERA, VORTICELLA, STENTORS, 



HYDRA, ZOOPHYTES, SPONGES, MOLLUSCA, CRUSTACEA, ETC. 



1 CIENCE has defined matter, space, time, and na- 

 tural history so infinitesimally, that the brain 

 becomes bewildered from want of some familiar 

 object to convey to the mind by comparison 

 the results exhibited. 



The precious metal gold can be reduced to a 

 film the four- millionth part of an inch in thick- 

 ness by manual ingenuity ; space measured and 

 divided the hundred-thousandth part of an inch 

 with truthfulness by a machine j electricity 

 proved to pass along a wire with the velocity 

 of five hundred and seventy-six thousand miles 

 in a second, and an object of the most elaborate 

 workmanship seized in every detail, and faithfully por- 

 trayed, by electricity and the camera, in the one-mil- 

 lionth part of the fraction of time denominated a 

 second. At the least, a million of living creatures of 

 delicate structure may be seen in active pursuit of 

 prey in a space not larger than a mustard-seed, and 

 a single one, increasing in twenty-four hours to the 

 enormous number of one hundred and forty millions, 

 is demonstrated by means of the philosophical instru- 

 ment the microscope, the construction of which we have been de- 

 scribing. 



