Microscopical Essays. 



469 



be told of animals many millions of times fmaller than a mite ;. for 

 there are fame animalcula fo fmall, that, upon calculation, the 

 whole earth is not found large enough to be a third proportional 

 to thefe little animals, and the whaie in the ocean.* Thele con- 

 fiderations are flill further heightened, by reflecting on the internal 

 ftructure of animalcula, for each mud have all the proportion, 

 fymmetry, and adjuftmeni of that organized texture, which is in- 

 difpenfibly neceflary for the feveral functions of life, and each 

 muft be furnifhed with proper organs, tubes, Sec. for fecreting 

 the fluids, digefting it's food, and propagating it's fpecies. 



Having thus given a general idea of the properties of animal- 

 cula, we now proceed to defcribe the various individuals, following 

 the arrangements of O. F. Muller,f and giving the reader the dif- 

 criminating characters by which he has diftinguimed them, abridg- 

 ing, enlarging, or altering the defcriptions, to render them in fome 

 inftanees more exact, in others lefs tedious, and upon the whole 

 I hope, more interefting to the reader. 



A METHODICAL DIVISION OF THE ANIMALCULA INFUSORIA** 



I. Thofe that have no external organs.. 

 t<, Monas : punctiforme. A mere point. [ 

 2, Proteus i mutabile. Mutable.. 



3. Volvox *: 



I * Cyclopedia Britannica, Art. Animalcule. 



+ Miiller Animalcula Infuforia, Fluviatilia et Marina*. 



