324 ^- J. Goldfarh 



many as nine polyps were present at the basal end of one piece. 

 These hydranths did not appear before the third or even the fourth 

 day after removal of the branches. The following table gives 

 some of the details of the experiment. 



TABLE 7 



Polyps regener- No. of branches 



Polyps regenerated ated ai oral ends that regenerated 



at basal end of 3 days 6 days 10 days in 10 days basal polyps 



Distal branches o 80% 160% 0% 90% 



Middle branches o 0% 100% 10% 70% 



Basal branches o 50% 120% 20% 50% 



The presence of polyps on the branch retards regeneration but 

 does not prevent the formation of polyps at the basal cut ends. 

 The figures, particularly in the last column, of the above table 

 seem to indicate a maximum tendency toward the production of 

 heteromorphic polyps on distal branches, less and less on middle 

 and basal branches, respectively. 



SUMMARY 



The mtd and basal thirds of a stem behave quite differently from 

 the distal third and from the lateral branches, in so far as the rela- 

 tive number of hydranths regenerated at the oral and basal ends 

 is concerned. The distal region of stems and the lateral branches 

 from any region produce a greater number of heteromorphic and 

 fewer apical polyps, than do the median and basal thirds of the 

 stem. Lateral branches from luhich polyps had not been removed 

 likewise produce more polyps at the basal than apical ends. 



Experiment 8. In the preceding experiments the presence of 

 lateral free cut ends may have introduced disturbing factors not 

 yet fully considered. In order to avoid these influences, some 

 or all of the lateral cut ends were ligated on a series of similar 

 stems as follows: 



a the apical end only; 



b the apical end and the two lateral ends on distal half of 

 stem; 



c the apical end and all the lateral ends; 



d all the lateral ends; 



