On certain Animalcules found in the fediment in gutters on the 



roofs of houfes. * 



1 HAVE been induced to publifh my difcoveries refpeding thefe 

 creatures, in order to fliew how wonderfully Nature has provided for 

 the prefervation of their fpecies. 



On the 25 th of Auguft, I faw in a leaden gutter at the fore part 

 of my houfe, for the length of about five feet, and the breadth of 

 leven inches, a fettlement of rain water, which appeared of a red co- 

 lour ; and, upon confidering that perhaps this colour might proceed 

 from fome red Animalcules, fimilar to thofe which I had feen in 

 muddy ditches, I took a drop of this water, which I placed before 

 the microfcope, and in it I difcovered a great number of Animal- 

 cules, fome of them red, and others of them green. The largeft 

 of thefe, viewed through the microfcope, did not appear bigger than 

 a large grain of fand to the naked eye ; the fize of the others was 

 gradually lefs and lefs : they were, for the moft part, of a round 

 fhape ; and in the green ones, the middle part of their bodies was 

 of a yellowifll colour. Their bodies feemed compofed of particles 

 of an oval fhape ; they were alfo provided with certain fhort and 

 llender organs or limbs, which were protruded a little way out of 

 their bodies, by means of which they caufed a kind of circular mo- 

 tion and current in the water : when they were at reft and fixed 

 themfelves to the glafs, they had the Ihape of a pear with a ihort 

 ftalk. Upon more carefully examining this ftalk, or rather this 

 tail, I found that the extremity of it was divided into two parts, 



• This fpecies of Animalcule is very minutely defcribed by Mr. Baker, in his Treatifes 

 on the Microfcope, and he has gtren to it the name of the wheel aoiaal : alfo ia Adams on 

 the Microfcope, 



