92 Pub. Puget Sound Biol. Sta. Vol. 2, No. 37 



CHART I. 



Graph 1 shows the reaction of a blenny to a difference of 16.2 cc. 

 carbon dioxide per liter between ends of a tank 120 centimeters long. The 

 greater concentration being to the right, the reaction is negative. Figures 

 at the left represent the time in minutes. 



Graph 2 shows the reaction of a fish (see foot-note page 86) from 

 deeper water under the same conditions as in graph 1. This fish shows 

 no observable response to the carbon dioxide. 



Graph 3 shows the reaction of a blenny to a difference of 7.29 cc. of 

 carbon dioxide per liter between the two ends. Although less marked the 

 reaction is still negative. 



Graph 4 shows the reaction of a blenny to a gradient from strong 

 alkali on the left to strong acid on the right. Note the increased activity, 

 the undoubted negative reaction to acid and the positive reaction to the end 

 (possibly thigmotaxis). 



Graph 5 shows the reaction of a blenny to a difference of 1.67 cc. 

 hydrogen sulphide per liter in a distance of 120 centimeters. This case 

 illustrates, better than the others shown, the general activity of a blenny 

 under experimental conditions. D represents disturbance by touching with 

 a pencil point. 



