116 



FACTORS AFFECTING CILIARY ACTIVITY 



trachea (Kordik, Bulbring and Burn, 1952), but accelerates the 

 activity of ciUa on the tentacles of Metridium (ten Cate, Coomans 

 and Walop, 1955). 



11. Effects of Other Chemicals on Ciliary Activity 



(a) Alkaloids. It has long been known that veratrine influences 

 the activity of cilia. Gray (1924) found that the lateral cilia of 

 Mytilus gill filaments could be activated by veratrine, or by 

 increasing the concentration of potassium ions, the tw^o being 

 mutually antagonistic. More recently, Aiello (1960) has come to 

 the conclusion that veratrine and potassium ions may actually 

 augment each other, since at a particular potassium concentration 

 an addition of veratrine increases the ciliary activity, and at a 

 particular veratrine concentration an addition of potassium 



Table 10. The effect of veratrine sulphate on the activity of 



LATERAL CILIA OF MytUuS GILLS. (FrOM AiELLO, 1960) (COPYRIGHT 



1960 BY THE University of Chicago) 



Figures in brackets are standard deviations. 



increases the ciliary activity. In normally active lateral cilia Aiello 

 found that the addition of veratrine sulphate produced marked 

 increases in both the frequency of beat and the metachronal vv^ave 

 velocity, as shown in Table 10. 



Gray (1928) suggested that the veratrine acts on the respiratory 

 processes which provide the energy for ciliary movement, as had 

 also been postulated fur muscle. However, Aiello found that the 

 respiratory rate and ciliary activity always changed together and in 

 the same way under the influence of veratrine, either alone or in 

 combination with respiratory inhibitors; he was not able to show 



