The Mechanism of Ciliary Movement. 123 



Table I. — The Effect of Mixtures of NV, K", Ca", and Mg" upon the Move- 

 ment of the Terminal Cilia of Myiilus. 



Time. 



Anion. 



30 mins. 



1 liour. 



2 hours. 



3 hours 



5 hours; exp. 

 discontinued. 



Ph. 



Chlorides Normal move- 



ment ; no 

 absorption of 

 water. 



Normal movement ; no absorption 

 of water. 



Nitrates 



Normal movement ; no absorption of water 



Iodides Very rapid movement ; 



no absorption of water. 



Normal movement ; no 

 absorption of water. 



Bromides 

 Acetates . . 



Normal movement ; no absorption of water 

 Normal movement ; no absorption of water 



Sulphates Very rapid movement ; 



no absorption of water. 



Normal movement ; no absorption 

 of water. 



Tartrates 



Citrates 



Normal I Slow Very slow 

 movement. | movement, movement. 



No absorption of water. 



No movement 



No movement ; no absorption of water 



7 -8 



7-8 



8 -0 



7-8 

 7-9 

 8 -0 



7-8 

 7-8 



Such experiments shew quite clearly that in a solution containing 

 balanced cations, the substitution of the normal anion chlorine by NCV, I', 

 Br', Ac', or SO/' is not attended by any interference with either the 

 activity of the cilia or the amount of water taken up by the cells. It is 

 possible that in the case of the iodide and sulphate mixtures there is 

 an actual increase in the rate of beat of the cilia, although the observed 

 effects may possibly be due to the slightly higher hydroxyl ion concentration 

 of these solutions. 



In considering the possible significance of the cessation of movement in 

 balanced solutions of tartrates and citrates, we are confronted with a purely 

 chemical problem. Calcium tartrate and calcium citrate are both very 

 sparingly soluble in water ; the same statement applies, though to a less 

 degree, to the magnesium salts. When, however, these salts are added to a 

 solution of the corresponding sodium salt, they dissolve to a very marked 

 extent. The suspicion arises that in making up a physiological mixture 

 of tartrates or citrates, the metals magnesium and calcium are not present 

 as free ions. This suspicion seems justified by the following facts. When 

 sodium phosphate and ammonia are added to a saturated solution of 



