Effects of Temperature on Tropical Marine Animals. 



II 



This result is confirmed by taking the average of all five rings; for here 

 also the increase in rate is in the form of a straight line practically coinciding 

 with that displayed by Ring A. This average curve is shown in figure 3. The 



S 



3 



c 



u 



a. 

 OS 



17 18 J9 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 



Degrees Centigrade 



Fig. 3, illustrating Table I. 



equation for the increase in rate with elevating temperature between 17.5 

 to 35 C, in these rings, is 3' = 4.85X + 54.5 and for Harvey's ring it is 

 y = 6.66jc + 50; where y is the rate at any given temperature above 17.5, 

 but below 30 in Harvey's and 35 on my curves, x is the temperature- 

 increment. Thus at 25.5 C.x = (25.5 17.5) = 8, and at 27.5 C. x = 10, 

 etc. The constants 54.5 and 50 are the rates of the rings at 17.5 C. 



Above 33 C, Harvey observed a sudden decline in rate, but my rings 

 did not display this decline until they had been heated to 35.5 to 39, and 

 Ring A did not display it even at 39 C, 



As Harvey states, these curves bear a close, although possibly only a 

 superficial, resemblance to those of enzyme actions. 



Certainly our observations are not in accord with the conditions necessi- 

 tated were the rate of the nervous impulse a simple chemical reaction, for 

 in this case the curve would be given by an equation of the form y = aC, 



