394 



LIBBIE H. HYMAN. 



given in the table. In experiment 7, the concentration employed, 

 1/20000 mol., was too weak to produce any effect, but the effects 

 of i/ioooo and 1/5000 mol. solutions are very striking. The 

 rate of regeneration of both apical and basal pieces is retarded, 

 but that of the apical pieces, in accordance with the hypothesis, 

 is more retarded so that the basal pieces regenerate on the whole 



the more rapidly. 



TABLE IX. 



RECORD OF MASS EXPERIMENTS ON THE RATE OF REGENERATION OF APICAL AND 

 BASAL HALVES WHEN BOTH ARE EXPOSED FOR A NUMBER OF HOURS AFTER 

 CUTTING TO THE SAME CONCENTRATION OF POTASSIUM CYANIDE. 



Columns give numbers of hydranths emerged at hours indicated. Exp. 10 

 control for exp. 13; exp. 21 for exp. 22. See Table III. 



The results of the experiments with ether are given in Table X. 

 Experiments 14 and 20 are mass experiments; 18 and 46 give 

 records of the number of hours required for the regeneration of 

 each piece. Experiments 14, 20, and 18 were performed in June 

 at room temperatures, except that exp. 20 was kept in the 

 refrigerator for part of the time after regeneration had begun. 

 Experiment 46 was performed in December at a temperature of 



