348 A. J. Goldfarb 



distal end. Sometimes the coenosarc from the two ends would 

 fuse close to the wound, or each wounded end may independently 

 regenerate a polyp, or less frequently the one or the other end only, 

 develops a polyp. Whether the injury was at the distal, middle 

 or basal part of the stem did not influence the regeneration. 



TABLE 21 



No. of stems No. polyps reg. at 



experimented upon Nature of the Operation injured ends in 6 days 



6 Stems punctured or slit at every internode i 



8 Sti."ms lacerated at every int;rnode 2 



6 Stems bent permanently o 



4 Stems bent and punctured at the bend o 



12 Stems slit and bent at point of injury 11 



// a sufficiently large area of ccenosarc is cut, irrespective of the 

 level of the stem, and the ivounds are prevented from closing imme- 

 diately, a relatively large number of hydranths are regenerated. 

 These adventitious polyps appear at the same time as the polyps 

 on the lateral branches, and seemed in no ivay to effect the regenera- 

 tion of the latter. 



Experiment zy. After stems had been experimented upon for 

 a long time and could no longer be made to regenerate, they were 

 cut into small pieces. Sometimes the lateral branches were also 

 cut close to the stem. The pieces cut from the distal regions never 

 regenerated, for the very obvious reason that coenosarc is never 

 present in the distal parts of stems. But the middle and basal 

 pieces regenerated an incredibly large number ot polyps at their 

 cut oral and basal ends. Some of the lateral branches which had 

 been cut close to the main stem also regenerated polyps. Here 

 again injury to the coenosarc accompanied by exposure to sea- 

 water rejuvenated the pieces in so far as rapid and extensive regen- 

 eration of polyps is concerned. 



EFFECTS OF DILUTED AND CONCENTRATED SEA-WATER"^ 



Experiment 28. Sea-water was diluted by the addition of tap- 

 water so as to make a graded series, with differences of 5 and some- 

 times 10 per cent, from normal sea-water to 50 per cent dilution. 



-^These experiments are based on Loeb's '91. See also Snyder '05, Archiv. f. Ent. Large numbers 

 of stems and branches were used. 



