146 ANIMALS KILLED IV. 
the pofterior part by means of the undulating or 
periftaltic motion. But we not only obferve the 
food difcharged from the body, we fee it enter ; 
that is, fragments of the tremella are feen convey- 
ed by the vortex to the animal’s mouth, infufion 
animalcula of various fizes, and particles of other 
fabftances. Some of the moft minute enter the 
origin of the cefophagus, traverfe the moving 
particle, and arrive at the paflage for the recep- 
cacle of the aliment (1). | 
The fame thing is obferved in another animal 
of the tremella, which is mentioned in the tract 
on infufion animalcula, pl. 1, fig. 10, R. The 
moving particle of this animalcule, for it has one 
as wellas the wheel animal, contraéts and dilates, 
while the aliment, colleéted by the vortex, pafles 
from the cefophagus to the ftomach. ‘Thus we 
{ee a particle in thefe animals, which, in fitua- 
tion, figure, and motion, refembles a heart, al- 
though it is not one, but an organ deftined for the 
we of the aliment. For thefe reafons do I af- 
cribe the fame ufe to that of the wheel animal. 
If I am right, the wheel animal has no 
heart: we fee no other part, no other organ, 
| that 
(1) This feems to be Muller’s Vorticella Furcata, p. 
299: There is no figure of it among the plates, for which 
a reafon is given ina note, Ido not remember to have » 
met with it—T. | : 
