440 CTLYZOA J BOWERBANKIA. 



transparency of the whole structure enables us to watch with no 

 interruption. The little animal when in full vigour is seen 

 projecting from its cell with the arms extended and the cilia in 

 active operation ; the upper part of the body being frequently 

 turned from side to side over the edge of the cell, the extremity 

 of which, from its peculiar flexibility, moves along with it. 

 The action of the cilia forms a kind of whirlpool, by which the 

 particles contained in the surrounding water are carried into the 

 funnel-like pharynx. By the contraction of its walls, they are 

 carried rapidly down the oesophagus into the gizzard, which 

 expands to receive them. Here they are submitted to a sort of 

 crushing operation ; the movement of its walls very much resem- 

 bling that which is seen in the dental apparatus of the Wheel- 

 Animalcules ( 929). Their residence in this cavity, however, 

 is only momentary ; and they are immediately propelled into 

 the true stomach below, where they become mixed up with its 

 contents, which during digestion* are always of a dark rich 

 brown colour, being tinged by the secretion of the biliary follicles 

 surrounding it. The food appears to be retained for a consider- 

 able time in the stomach, and may frequently be seen to pass 

 back into the gizzard, for the purpose of being again submitted to 

 its operations. After being subjected to the digestive process in 

 the stomach, the particles which remain are transmitted into the 

 intestine ; but previously to their entering it, they are seen to 

 rotate for some time about its orifice, the movement being pro- 

 duced by the action of the cilia that fringe it. The granular 

 matter accumulates in little pellets in the intestine ; and when 

 these pass out from its extremity, they are immediately whirled 

 off to a distance, by the same action of the cilia upon the arms 

 as that which produces a current towards the mouth. 



1075. Considerable power of selection appears to be enjoyed 

 by these animals in regard to their food. The movements of 

 the cilia which fringe the tentacula, seem entirely under the con- 

 trol of the individual ; and by their vibrations currents of water 

 are produced, which bring particles of various kinds of living 

 and dead matter to the entrance of the alimentary canal. It 

 has been sometimes noticed that animalcules, which have thus 



