A. R. MOORE 



507 



accounted for if we assume it to be due to the formation of a com- 

 pound between the nicotine and sbme substance of the cerebrum in 

 critical concentration, and that sufficient nicotine is taken into the 

 squid's body during the first minute to accomplish this result, and 

 further that the uncombined nicotine is retained during the 6 or 7 

 minutes necessary for the reaction to reach the desired point. The 

 assumption that this reaction or series of reactions is essentially 

 chemical in nature is supported by the effect of the temperature on 

 the length of the latent period. 



Temperature. 

 C. 



24° 

 14° 



24- 

 14= 



2f 



Time. 



fntn. 



Temperature 

 coefficient. 



20} ^■'' 



n} 2.S3 



Si 2-" 



The rate of the reaction is increased approximately 2.8 times for an 

 increase in temperature of 10°C. This value falls in well with the 

 temperature coefficients of other life phenomena. 



The effect of the concentration of the nicotine on the latent period 

 of the mantle spasm is shown below. T° = 24°. t = time in min- 

 utes. V = the velocity of the process. 



From these results it appears that the velocity of the process varies 

 approximately as the cube root of the concentration of the nicotine. 



