172 POLYGASTRICA. 



provided with many stomaclis, calls tliem 

 polygastricay from the Greek trokvs, (pohis) 

 and yaarrjp, {goster) a stomach. If they are 

 suffered to remain a short time in water con- 

 taining finely divided particles of colouring 

 matter, the appearance of these particles in 

 their transparent bodies, is such as to indicate 

 that they contain numerous globular cavities. 

 Still this point cannot be regarded as com- 

 pletely decided; and by many persons the 

 views of Ehrenberg are declared to be un- 

 tenable. 



Round the mouths of these animalculse there 

 are found ciliay moving with a rapidity that 

 astonishes the observer : they look like hairs 

 vibrating with a vehemence that is incredible 

 till witnessed. This vibration produces cur- 

 rents in the fluid containing the infusoria, 

 and thus the food on which they live floats into 

 the mouth. At the same time, they are ena- 

 bled by the cilia also to swim quickly about. 

 Totally invisible to the naked eye, a good 

 quarter of an inch achromatic presents them to 

 the view of the microscopist in a little globule 

 of water. "When," says an eminent physi- 

 ologist, " a number of dissimilar forms are 

 assembled in one drop of water, the spectacle 



