20 THOUGHTS ON ANIMALCULES. 



whole. Their vegetable nature was, therefore, at first, 

 deemed unquestionable ; but M. Trembley having no- 

 ticed the spontaneous motions of the mutilated polypes as 

 they advanced to perfection, with great sagacity inferred 

 that they were true animals, possessing a structure which, 

 like that of certain plants, admitted of subdivision, with- 

 out destroying its vitality or powers of reparation. 



It may easily be conceived how great was the aston- 

 ishment excited by this discovery; and its announce- 

 ment was received with hesitation by some, and ridi- 

 culed by others. Such, however, was the curiosity 

 awakened among the naturalists of this country, that 

 the then President of the Royal Society, Martin Folkes, 

 repeated the experiment upon some polypes sent to him 

 by M. Trembley from Holland ; for, although the ponds 

 and rivulets around London abounded in these animals, 

 and their existence had been made known forty years 

 previously by the celebrated Leeuwenhoek, the fact 

 appears to have been entirely overlooked or forgotten. 

 Subsequently, Mr. Henry Baker, an eminent micro- 

 scopical observer, verified the statements of M. Trem- 

 bley in every essential particular, and published the 

 result of his experiments in an interesting volume, 

 which is still the best English work on the subject*. 



* " An Attempt towards the Natural History of the Polype. By Henry 

 Baker, F.R.S., London, 1743." One volume, 8vo, with numerous ligno- 



