30 LEWIS R. GARY 



and from that time on the rate of regeneration is practically 

 equal from both halves (table 2 and fig. 7). 



4. When all the sense organs are removed from a disk and the 

 halves insulated muscular activity may be maintained in one- 

 half by forming an endless labyrinth of the sub umbrella tissue 

 and initiating a circuit wave of contraction by induction shocks. 

 Under these conditions the regeneration is faster from the acti- 

 vated than from the inactive half disk. The difference is, how- 

 ever, not nearly so great as when the sense organs are removed 

 from only one of the in.sulated halves of a disk (table 3 and fig. 9) . 



5. The comparison of the rates of regeneration of the halves 

 of a disk one-half of which retains its sense organs, while a cir- 

 cuit wave of contraction is maintained in the muscles of the 

 other half, shows that the half disk the muscles of which are 

 contracting under the control of the sense organs regenerates 

 faster, although the rate of pulsation of the activated half is 

 more than three times that of the former (table 4 and fig. 11). 



6. The study of the influence of the sense organs on general 

 metabolism — as shown by CO2 production — has shown that the 

 metabolism of Cassiopea is influenced by the sense organs in a 

 manner quite in accord with the differences in the rates of re- 

 generation under the several sets of experimental conditions. 



The influence of the nervous system on the earlier stages of 

 regeneration has been noted by several earlier investigators, but 

 apparently no importance has been attached to it. 



These experiments indicate that the rate of regeneration is 

 simply one expression of the general metabolic activity of an 

 animal, and as such is subject to the influence of the nerve centers 

 as are many other functional activities. 



