156 



LESLIE B. AREY 



teinponituiv is ])urely physical, the coefficient of 2± for 10°(\ 

 is of interest, on account of its agreement with the value found 

 for the temperature coefficient of various vital processes as well 

 as of ordinary chemical reactions. 



The incomplete data concerning the maximum lengths of 

 the inner members of rods are hardly significant, although 

 both of the mean values at 15°C. and 25°C. are slightly above 

 the one measurement at 5°C. The EhrHch-Biondi stain was 

 used on most of these preparations and it was only rarely that 

 the rod ellipsoid took the stain sufficiently to render its identi- 

 fication certain. 



TEMPERATURE IN DEGREES CENT. 



Fig. A. Plot showing the relation between temperature and niyoid length 

 in the cone cells of Abramis. 



Table 6 gives measurements from two retinas which had been 

 subjected to extreme temperatures in the light. The measure- 

 ments for the cone myoids are identical, and in no one of the 

 four fishes was there a demonstrable change ascribable to 

 temperature under these conditions. It should be noted that 

 the cone measurements at 5°C. in the dark (table 3) are either 

 equal to or, as in this case, are actually smaller than those repre- 

 senting the highly retracted light condition. This dependence 

 upon temperature was taken advantage of in all experimenta- 

 tion to be described later where elongation of the cones was 



