82 



FACTORS AFFECTING CILIARY ACTIVITY 



of the Arrhenius equation (K^Ce"*"^^^) to the results given in 

 Table 5. This equation is more conveniently expressed as log 

 K = C — /x/RT, vv^here K is the rate of the process affected by 

 temperature, C is a constant, /x is the temperature characteristic, 



Table 5. The effect of temperature on the frequency of beat, 

 metachronal wavelength and metachronal wave velocity of 



Steiltor MEMBRANELLES. 



R is the gas constant and T is the absolute temperature. A 

 straight line will be obtained when log k is plotted against 1/T if 

 the data fit the equation, and a temperature characteristic for these 

 data can be calculated from the gradient of the line. 



Graphs of this type, showing the effect on frequency and 

 metachronal wave velocity of Stentor membranelles of tempera- 

 tures in the range 0-25 °C are given in Fig. 19. Values of /x 

 calculated from a number of experiments on Stentor gave an 

 average for frequency of 11,330 cal, and for wave velocity of 

 7520 cal; the difference between these two averages is significant. 



The fact that both of these lines are straight suggests that we 

 can expect the effect of temperature on both activities to be 

 simple rather than complex. Gray (1923) found that the changes 

 in activity of Mytilus frontal cilia corresponded very closely with 

 changes in oxygen consumption caused by change in tempera- 

 ture, so that it appears that the rate of doing work is closely linked 

 with the rate of respiration. 



