Abstracted by William M. Goldsmith, author 

 Southwestern College, Winfield, Kansas. 



The process of ingestion in the ciliate, frontonia. 



The food of the ciliate, frontonia, is primarily diatoms, 

 desmids, euglenas, filaments of oscillatoria, and various other 

 microscopic plants. The mouth is normally very small, but may 

 be expanded to approximately two-thirds the length of the body 

 without injuring the organism. Five factors are involved in 

 the process of ingestion of material longer than the expanded 

 width of the body of the frontonia. A. Action of oral cilia: The 

 cilia about the mouth of frontonia exert a direct pull upon the 

 incoming food. B. Action of the locomotor cilia: The cilia of 

 the body drive the organism forward and thus force the stationary 

 food into the mouth. C. The rotation of the body axis: The 

 end of the fiber usually enters the mouth and passes anterodorsally 

 until it comes in contact with, and exerts a pressure upon, the 

 aboral wall, after which the frontonia swdngs around and releases 

 the tension. Points of contact between the ingested particle and 

 the inner side of the body membrane are called tension points. 

 D. Body contractions: A series of sharp contractions of the body 

 wall assists in relieving certain other tension points. E. Cyclosis: 

 Cyclosis probably aids by moving the end of the fiber around the 

 wall. Unusual and fantastic figures are produced through the 

 contortion of the organism by the ingested food. 



