LECTURE XII. 
225 
^ules; the common ova] Cyclidiiim 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 Animalcuiar 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 END 
LECT. II. 
a 
