C I LIAR Y A CTION. 



NOTE ON CILIARY ACTION. 



In the case of ciliary action we have an example of a movement 

 which, though not strictly a vital movement, like that of the amoeba 

 (see p. 39), is really dependent upon changes which are a direct result 

 of 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 may indeed be actually prolonged into the base of 

 the cilium. The vibratile movement is probably due to an alteration 

 taking place in the tension of the fluid which pervades the tissue, 

 induced by the action of the living matter of the cell. The rate of 

 vibration varying according to the rapidity with which the living matter 

 of the cell absorbs nutrient substances, and undergoes conversion into 

 formed matter, or in other words, the rapidity with which the formation 

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

 When ciliary action ceases, we cannot, I think, say that each individual 

 cilium dies, for after all action has ceased a little alkaline fluid will 

 cause the cilium to vibrate again actively. We must not, therefore, 

 infer that the dying cilium has been revived or the dead cilium 

 revitalized by. the liquor potassse, for the fact seems rather to point to 

 the conclusion that the action of the cilium which occurs during life 

 is due to physical changes, and is not a vital action. 



My friend, Dr. Rutherford, has suggested 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 advocated by me in the following pages, and if the cilium 

 itself were composed of living matter, like the body of an amoeba, 

 such an objection would undoubtedly hold : but if, on the other 

 hand, the movement is physical, due to alterations in the currents 

 of fluid through the cell, we should expect that it would continue 

 longer at the apex than at the base, for the simple reason that 

 an impulse which would be sufficient to make the thin free part vibrate 

 freely would be insufficient to move the thicker portion attached to 

 the cell. We cannot say that the cilium dies from base to apex, 

 for the whole vibratile appendage is as destitute of life while it is yet 

 vibrating actively, as after it has ceased to move, and if we could only 

 make fluid flow through the cell after its death interruptedly in the same 



