22 



LEWIS R. CART 



influence of its sense organs. The half disk with its sense organs, 

 although pulsating much more slowly than its activated mate 

 shows a considerably higher rate of regeneration than the latter. 



9 



Fig. 9 Curves to show the comparative rates of regeneration between-the 

 halves of 40 disks from which all of the sense organs have been removed, while 

 the subumbrells muscles of one-half of each disk are activated by a circuit wave of 

 contraction. The upper (solid) line shows the regeneration of the activated half 

 disks, while the lower (broken) line shows the regeneration of the half disks with- 

 out sense organs or activation. The divisions along the ordinate represent the 

 amount of regeneration in millimeters. Those along the abscissa the time of 

 regeneration in days. 



That the influence of the sense organs upon the rate of regen- 

 eration difl'ers m no essential respect from that exercised upon 

 the general metaboUc activity of the entire disk is shown by 

 comparing the amounts of CO2 produced in a given time by half 



