346 INFUSORY WORMS. 



ness as, in general, to elude the sharpest sight, unless assisted by 

 glasses. The ancients therefore were totally unacquainted with this 

 class of beings. To them the mite was made the ne plus ultra, 

 or utmost bound of animal minuteness ; but the moderns, assisted 

 by the invention of the microscope, have discovered whole tribes of 

 animals, compared to which even mites may be considered as a kind 

 of elephants. These minute beings are chiefly to be observed in 

 fluids of various kinds; and principally in such as have had any ani- 

 mal or vegetable substances infused in them; and for this reason 

 they are often called in modern zoology, by the title of animalcula 

 infusoria, or infusorial animalcules. A most extraordinary idea 

 was entertained by the celebrated Count de BufTon, relative to these 

 animalcules ; viz. that they were not real animals, but a kind of 

 organic particles or moleculae, which were capable, under certain 

 circumstances, of being formed into animated beings. The experi- 

 ments of Spallanzani and others have, however, completely over- 

 thrown this chimerical and absurd theory of the Count de BufVou j 

 and indeed one would hardly think it possible for any person of 

 unprejudiced mind, nay one may even add, of common sense, to 

 view the several animalcules in fluids, and at the same time to doubt 

 of their being real animals, Their rapid and various motions; their 

 pursuit of the smaller kinds on which many of the larger pteyj 

 their avoiding each other as they swim ; the curious and regular 

 structure of their bodies ; and their whole appearance, form the 

 most convincing proofs of their real animal nature aud life. 



Animalcules, as before observed, are most frequently found in 

 fluids ; but this is a doctrine that has not always been clearly under- 

 stood, and has been productive of some erroneous ideas in natural 

 history. Some wrilers, for instance, have asserted that almost 

 every kind of fluid abounded with animalcules ; and that wines and 

 spirits exhibited legions of them. This, however, is so very far 

 from the truth, that none are ever to be discovered in inflammable 

 spirits, or in any fermented liquor that has not passed either into 

 the state of vinegar, or that is not grown completely vapid. As 

 almost all extraordinary discoveries are liable, when related by un- 

 skilful persons, to have their circumstances exaggerated by addi- 

 tional ornaments, we need not be surprized that this has been the 

 case relative to the history of microscopic animalcules. No sooner 

 did the microscopical observations of Leewenhoeck and a few others 



