RATE OF REGENERATION IN CASSIOPEA 5 



muscular activity. Fourth, disks prepared in the manner just 

 mentioned were treated with solutions of oxahc acid which will 

 destroy the sense organs without seriously injuring the muscular 

 system or the conducting portions of the nervous system. Fifth, 

 specimens from which all sense organs had been removed and 

 with the halves insulated in one of which muscular activity was 

 initiated by means of an induction shock and maintained as a 

 circuit wave of contraction in an endless labyrinth of muscle 



Figs. 1 and 2 Experiments of type 1. 



Fig 1. Active disk with sense organs intact, and with pieces of tissue cut frona 

 the margin of the disk between them. 



Fig. 2 Inactive disk from which all of the sense organs have been removed. 



tissue, instead of being controlled, as normally, by nerve im- 

 pulses arising from the marginal sense organs (fig. 6). Sixth, 

 specimens with insulated halves in one-half of which muscular 

 contraction was maintained by means of a circuit wave of con- 

 traction while the pulsation of the other half was under the normal 

 control of its sense organs (fig. 7). 



EXPERIMENTS WITH ENTIRE DISKS 



When the rate of regeneration of a series of active and inactive 

 entire disks is compared it is found that in about 75 per cent of 

 all the experiments the regeneration is most rapid in the active 



