INFUSORIAL ANIMALCULES. 54/ 



less abundantly with cilia, which serve various important pur- 

 poses. Sometimes they are only disposed around the mouth, 

 towards which they produce a vortex of fluid, that brings a sup- 

 ply of alimentary particles. Where the digestive cavity has a 

 separate termination, this also is usually fringed with cilin, by 

 the action of which the particles rejected are thrown off to a 

 distance. And, in many of the higher species not enclosed in a 

 silicious envelope, the whole body is beset with rows of these 

 little filaments ; by the action of which every possible variety of 

 movement seems to be produced. 



1204. The name Polygastrica was applied to these Animal- 

 cules by Ehrenberg, in consequence of his belief that they 

 possess a large number of distinct stomachs, or cavities for the 

 reception and digestion of aliment. This belief is founded on 

 the appearance which many of them present, when they have 

 been allowed to remain for a short time in water, in which finely 

 divided particles of colouring matter are suspended. The par- 

 ticles are observed to be drawn towards the mouth, by the action 

 of the cilia with which most of them are provided ; and before 

 long, the whole of the transparent body is seen to be studded 

 with coloured globules of a uniform size, many times larger 

 than the separate particles themselves. Sometimes these globules 

 are very numerous, amounting to more than one hundred. If 

 two kinds of colouring matter be put into the water, as for in- 

 stance carmine and indigo, separate pink and blue globules will 

 be seen in the bodies of some of the Animalcules. 



1205. From these facts it was inferred by Ehrenberg, that 

 a large number of globular cavities exist in the substance of 

 the body, into which the food is received. He considers that 

 sometimes these communicate only with the mouth, as in the 

 Monas ; but that in general they are arranged along an intestinal 

 tube into which they open by a short neck. The course of this 

 tube he infers from the disposition of the coloured globules, rather 

 than from any more distinct indication of its presence. Thus 

 in the Vorticella, he thinks that it returns to the neighbourhood 

 of the mouth ; whilst in Enchelys and Leucophrys it terminates 

 at the opposite extremity of the body, running straight in the 

 first from one end to the other, and in the second making two 



