Microscopical Essays. 467 



The animalcula are infinitely fraaller than fpermatic animals, 

 and of a very different fhape ; the truth of which every accurate 

 obferver will foon be convinced of, whofe curiofity may lead him 

 to compare them, and he is perfuaded they will find they are no 

 way akin. 



Having learnt from Mr. De Sauffure, of Geneva, that he found 

 one kind of thefe animalcula infuforia that increafe by dividing 

 acrofs into nearly two equal parts, and that the infufion was made 

 from hemp-feed, he procured a quantity of this feed, fome of it 

 he put into New River water, fome into diftilled water, and fome 

 into very hard pump water ; the refult was, that in proportion to 

 the heat of the weather, or the warmth in which they were kept, 

 there was an appearance of millions of minute animalcula in all 

 the infufions ; and, fome time after, fome oval ones made their 

 appearance; thefe were much larger than the firft, which ilill 

 continued ; thefe wriggled to and fro in an undulatory motion, 

 turning themfelves round very quick all the time that they moved 

 forwards. 



Mr. Ellis found out, by mere accident, a method to make their 

 fins appear very diftindly, efpecially in the larger kind of ani- 

 malcula, which are common to molt vegetable infufions, fuch as 

 the terebella. This has a longifh body, with a cavity or groove 

 at one end, like a gimlet: by applying a fmall ftalk of the 

 horfefhoe geranium, (or geranium zonale of Linnaeus) frefh 

 broken, to a drop of water in which thefe animalcula are fwim- 

 min-. #€ Taail find that they will, become torpid inftantly, con- 

 tracting themfelves into an oblong. oval Ihape, with their fins ex™ 

 tended like fo many bridles all round their bodies. The- fins are 



o L 2 *** 



