LECTURE XII. 



eules: the common oval Cyclidium never fails to 

 appear in countless swarms in any kind of vegeta- 

 ble infusion after the space of a few days ; as in 

 infusions of hay, beans, wheat, and other sub- 

 stances. Its motions are generally very rapid. 



The smallest of all the Animalcular tribe be- 

 long to a genus called Monas : its character is 

 an oval or roundish body, with a central point 

 or speck. Whenever any kind of soft vegetable 

 substance has been either infused or boiled in 

 water, the water, when set by, will not fail to ex- 

 hibit animalcules of this genus, sometimes in the 

 space of twelve, but assuredly in the space of 

 twenty-four hours afterwards. The smallest of all 

 the genus, and the smallest of all animal beings, 

 so far as human research is capable of discovering, 

 is a species called Monas Termo, which when sur- 

 veyed by the utmost powers of the microscope, 

 still appears but as a kind of moving point, hav- 

 ing merely a sensible diameter. It is found in 

 various vegetable infusions, appearing in the space 

 of a few hours. 



THE EN1> 

 LECT. II. 2 



