594 



GABRIELE KASS-SIMON 



ted. At 1.5 mg/ml ail proximal and distal halves were inhibited. Thus, where in- 

 hibition is less than total, RNase prevents basai plate régénération more readily 

 than it does tentacle régénération. 



2. Treatment with Actinomycin 



The results are summarized in Table 12. (a) Intact animais subjected to 

 2 gamma/ml actinomycin die between 72 and 96 hours after the beginning of 

 treatment. (b) Animais subjected to pretreatment only and those transected before 

 treatment begin to die at times comparable to intact animais subjected to con- 

 tinuous treatment. (c) When treatment is begun 10 hours after transection. the 

 number of proximal halves regenerating tentacles drops significantly (X 2 =7.5 9 



Table 12. 



The Effect of Actinomycin C (Bayer) on Basai Plate and Tentacle Régénération. 

 N= Number of Animais. N[ = Number of Inhibited Animais. N x = Number of Regenerated 

 Animais. %i= percent Inhibition. In any given row proximal and distal halves are derived 

 from the same animais. Concentration 2 gamma/ml. 









Tentacle Régénération 

 in Proximal Halves 



Basai Plate Régénération 

 in Distal Halves 





Treatment 



N 



Ni 



N r 



%i 



N 



Ni 



N r 



%i 



(1) 



For 24 Hours prior to 

 Transection Only . . 



7 



5 



2 



71% 



7 



7 







100% 



(2) 



From Transection for 

 15 Hours Only . . . 



10 



10 







100% 



9 



5 



4 



55.5% 



(3) 



From Transection un- 

 til Death After Interval 

 of : Minutes .... 



59 



58 





98.3% 



57 



55 



2 



96.5% 



(4) 



5—10 Minutes . . . 



18 



15 



3 



83.3% 



18 



16 



2 



88.8% 



(5) 



Between l / 2 and 1 Hour 



24 



18 



6 



75.0% 



26 



18 



8 



69.2% 



(6) 



2 Hours 



6 



5 



1 



83% 



6 



6 







100% 



(7) 



3 Hours 



7 



5 



2 



71% 



7 



7 







100% 



(8) 



Between 4 and 6 Hours 



19 



13 



6 



68.4% 



19 



16 



3 



84.2% 



(9) 



10 Hours 



23 



5 



18 



21% 



24 



16 



8 



77% 



(10) 



12 Hours 



18 



4 



14 



22.2% 



20 



1 



19 



0.5% 



(H) 



17 Hours 



7 







7 



0% 



7 







7 



0% 



