Microscopical Essays. 



takes place in the middle, forming a kind of neck, that becomes 

 fmaller every inffant, till they are enabled by a flight degree of 

 motion to feparate from each other. Thefe animalcula, in gene- 

 ral, ftudioufly avoid each other • but when they are in the labour 

 of multiplication, and the divifion is in great forwardnefs, it is 

 not uncommon to fee one of them precipitate itfelf on the neck of 

 the dividing animalcula, and thus accelerate the feparation. 



Another fpecies, when it is on the point of multiplying, fixes 

 itfelf to the bottom of the infufion ; it then forms an oblong 

 figure, afterwards becomes round, and begins to turn rapidly, as if 

 upon an internal center, continually changing the. direction of its 

 rotatory motion ; after fome time, we may perceive two 1 ines on 

 the fpherule, forming a kind of crofs • foon after which, the ani- 

 mal culum divides into four, which grow, and are again fubdivided.. 



Some multiply by a longitudinal divifion, which in one kind 

 begins in the fore-part, and others in the hind-part ; from another 

 kind a fmall fragment is feen to detach itfelf,. which very foon 

 acquires the form of the parent animalculum. Laflly, fome propa- 

 gate in the fame manner as thofe we deem more perfect animals. 



From what has been faid, it appears clearly that their motions 

 are not purely mechanical, but are produced by an internal fpon- 

 taneous principle, and that they mufl therefore be placed among 

 the clafs of living animals, for they poffefs the ft rongeft. marks, 

 and the moft decided characters of animation ; and confequently, 

 that there is no foundation for the fuppofition of a chaotic and 

 neutral kingdom, which can only have derived it's origin from a 

 very tranfient and fuperficial view of thefe animalcula. 



It 



