§40 ANIMALCULA OF INFUSIONS. t, 



the propagation ; and we mufl admit that they 

 are intended for fome other ufe, though to us un- 

 known. The whole fubftance of the arm polypi, 

 which multiply by divifion, is alfo granulated ; 

 and M. Trembley has demonftrated, that thefe 

 grains have no fliare in the multiplication. 



In the extenfive empire of animalcula, natu- 

 ralifts are acquainted with one fpecies only, as 

 far as I know, which multiplies in the manner 

 Ellis defcribes. This is the celebrated vohox, 

 apparently fo named from revolving on itfelf in 

 its progreflive motion, firil difcovered byLeeuwen- 

 hoeck, and then found by other naturalifts. From 

 the great tranfparency, like moil animalcula, the 

 internal ftru(3:ure is clearly feen ; and fome obfer- 

 vers have already difcovered the young within 

 even to the fifth generation. In my long obfer- 

 vations on infufions, I have found two particu- 

 larly abounding with the volvox, hempfeed and 

 tremella. There are often many in the putrid 

 water of dunghills. Thefe animals are originally 

 very fmall, but grow fo large as to be percepti- 

 ble by the naked eye. They are of a greenifh 

 yellow colour, a globular fhape, of a very tranf- 

 parent membranaceous fubftance, and ilrewed 

 with the moft minute globules within. Three 

 volvoxes of different fizes are reprefented, Plate 

 I. fig. 5. Examined with a very powerful mag- 

 nifier, thefe globules are difcovered to be fo 



many 



