CILIAR Y A CTION. 237 



indirect result of vital changes taking place in adjacent 

 living matter. 



Ciliary action is not strictly a vital movement, like that 

 of the amoeba (see p. 202), but is really dependent upon 

 changes which directly result from vital phenomena. The 

 cilium itself is not composed of living matter, but its base 

 is certainly, in very intimate relation with matter that is 

 alive. The latter is indeed actually prolonged into the 

 shaft of the cilium. The vibratile movement is probably 

 due to an alteration taking place in the tension of the fluid 

 which pervades the tissue of the cilium, and is induced by 

 the action of the living matter or bioplasm. The rate of 

 vibration of the cilium is probably determined by the 

 rapidity with which the living matter absorbs nutrient sub- 

 stances, and undergoes conversion into formed matter, or 

 in other words, by the rapidity with which the formation of 

 new living matter and the death of the old takes place. 



When ciliary action ceases, we ought not, I think, to 

 say that each individual cilium dies, because after all action 

 has ceased a little alkaline fluid will cause the cilium to 

 vibrate again actively. The alkaline fluid cannot restore 

 life. We ought not infer that the dying cilium has been 

 revived or the dead cilium revitalized by the liquor potassae. 

 The fact seems rather to point to the conclusion that the 

 action of the cilium which occurs during life is due imme- 

 diately to physical change, and only indirectly results from 

 vital action. 



It has been suggested by Dr. Rutherford, that the fact 

 of the cessation of movement at the base of the cilium, 

 while the thin part still continues to vibrate, might be 

 advanced as an argument against the views upon vital 



