486 



Microscopical Essays 



This animalculum feems to be a kind of medium between the 

 volvox pillula and the gonium pectorale, being like the one com 

 pofed of green fpherules, and in form refembling the other. 



It eonfifts of a congeries of equal globules of a greenifti colour, 

 with a bright fpot in the middle ; the whole mafs is fometimes of 

 a fpherical form, fometimes oval, without any common mem- 

 brane ; a kind of halo may be perceived round it, but whether 

 this is occafioned by the motion of any invifible hairs has not 

 been difcovered. The mafs generally moves from right to left, 

 and from left to right ; fcarce any motion can be difcovered in 

 the globules themfelves. It was found in the month of Auguft, 

 in water where the lemna polyrrhiza was growing. Two mafTes 

 of thefe globules have been feen joined together. They contain 

 from four to fifty of the globules, of which a folitary one may 

 now and then be found. 



24. Volvox Vegetans. 



Volvox ramulis fimplicibus & dichitomis, rofula globulari ter- 

 minals. A volvox with fimple dichitomous branches, terminating 

 in a little bunch of globules. 



It eonfifts of a number of floccofe opake branches, which are 

 invifible to the naked eye ; at the apex of thefe there is a little 

 -congeries of very minute oval pellucid corpufcles. Muller at firft 

 thought it to be a fpecies of microfcopic and river fertularia ; but 

 .afterwards he found the bunches quitting, the branches, and 

 fwimming about in the water with a proper fpontaneous motion. 

 Many old branches were found deferted of their globules, while 



