96 



THE VITAL FUNCTIONS. 



situations, and arrangement of the organs of 

 digestion in the Infusoria. They differ also in 

 their degree of complication ; but without any 

 obvious relation to the magnitude of the ani- 

 malcule. The Monas atomus, the minutest of 

 the whole tribe, exhibits a number of sacs, 

 opening by as many separate orifices, from a 

 circumscribed part of the surface. In others, as 

 in the Leucophi^a patiila, of which Fig. 255 

 represents the appearance under the micro- 



scope, there is a long alimentary canal, tra- 

 versing the greater part of the body, taking 

 several spiral turns, and furnished with a great 

 number of c(Bca; a term which denotes blind 

 pouches, proceeding laterally from any in- 

 ternal canal, and having no other outlet. 

 These cavities become filled with coloured 

 particles, immediately after their entrance 

 into the alimentary canal ; and must there- 

 fore be considered as so many stomachs 



