RATE OF REGENERATION IN CASSIOPEA 



25 



disks which had been subjected to operations similar to those 

 used in the regeneration experiments. The CO2 production of 

 small circular pieces of subumbrella tissue cut from the near bell 

 margin of disks under different experimental conditions was in 

 every instance shown, from determination with the biometer by 

 Dr. S. Tashiro, to be parallel to the rate of regeneration of the 

 entire half disk from which it had been removed. In another 

 set of experiments, the results for which will be published else- 

 where, the half disks upon each of which the appropriate opera- 



Fig. 10 To show the operation used in experiments of type 6. The sense or- 

 gans were removed from one-half of the disk, an equal amount of tissue from the 

 margin between the sense organs on the other half and the insulation of the halves 

 brought about by the removal of strips of subumbrella ectoderm. A circuit 

 wave of contraction was maintained in a labyrinth of subumbrella tissue of the 

 half from which the sense organs had been removed. 



tion had been performed were kept in separate closed vessels of 

 sea water for the same length of time, and then the comparative 

 amounts of CO2 produced determined, using normal sea water 

 taken at the time of the beginning of the experiment as the stan- 

 dard of measurement. Here again, as in the tests with the bi- 

 ometer, the total metabolic activity of disks under the several 

 sets of experimental conditions showed the same relation to the 

 presence or absence of the influence of the sense organs as did 

 the differences in rate of regeneration under the same type of 

 experimental conditions. 



