DISCUSSION 



87 



ity occurs along the length of the blue worm, 

 Octolasium cyaneum (O'Brien, 1957). Guttman 

 (1935) and Shapiro (1937) recorded inverted, 

 U-shaped curves in respiratory rate along the 

 length of the optic nerve of Limulus polyphemus , 

 the horseshoe crab, at 28° C. to 31° C. (but not 



at 16° C). The axon of Limulus shows most of 

 the activity when compared with the sheath. 

 Lastly, Kubista (1956) found a decrease in the 

 rate of oxygen uptake along the thorax of the 

 cockroach {Periplaneta americana) , with a rise 

 again in the region of the abdomen. 



