76 



BIOLOGY: GENERAL AND MEDICAL 



Under abnormal conditions many of the fixed cells 

 of the higher animals show that they retain the amoeboid 

 movement to a limited extent. 



Ciliate and Flagellate Movements. Cilia are minute 

 short hair-like processes with which many cells are 

 provided; flagella, larger, coarser, whip-like processes. 

 Between the two there is no sharp line of distinction, 

 and the numerous cilia of the bacteria are universally 

 known as flagella. 



FIG. 22. Amoeba verrucosa coiling up and ingesting a filament of oscillaria, 

 After Rhumbler (1898). The letters a to g, show successive stages in the 

 process. (Jennings.) 



Cilia and flagella are specialized processes of the cell 

 substance, composed of hyaloplasm. They are analo- 

 gous to pseudopods, but differ from them in their more 

 uniform and delicate structure and in being permanent 

 instead of temporary structures. They can be made 

 use of to assist in the classification of many organisms. 



Cilia are utilized for the double purpose of motion 

 and locomotion. Thus many of the infusoria are 

 covered with minute hair-like cilia of uniform size, 

 whose synchronous vibrations propel the organisms 



