Changes in Salinity and Effects on Regeneration, etc. 



91 



Fig. 4. 



Eudendrium, 6 days. 

 Eudendrium, 3 days. 

 Cassiopea. 

 . . Tubularia. 



1. Regeneration takes place in a more limited variation from the norm 

 than either Tubularia or Cassiopea, i. e., the maximum salinity in which 

 regeneration takes place is 120, the minimum is 60. 



2. Maximum regeneration is intermediate, 65 per cent solution for 

 Tubularia, 85 for Eudendrium, and 95 for Cassiopea. 



3. Normal or supernormal regeneration in Tubularia occurs over a wide 

 range of solutions, from norm to 50 per cent; in Eudendrium it is inter- 

 mediate, 100 to 80 per cent; in Cassiopea most limited, 100 to 85 per cent. 



4. The nature of the curves varies. Tubularia and Cassiopea have 

 asymmetrical curves, Eudendrium almost symmetrical, i. e., beyond the 

 optimum solution, increased dilution or concentration is equally injurious. 



Two sets of observations after 3 and 6 day intervals afforded the oppor- 

 tunity of comparing these with corresponding sets of observations on 

 Cassiopea. The regeneration in Eudendrium is given in table 5. 



Table 5. 



It is apparent that the same phenomenon observed in Cassiopea occurred 

 in Eudendrium, namely, that with increased intervals there is a greater 

 relative regeneration, not in the optimum nor hypertonic solutions, but in 

 the more dilute solutions, such as 75 and 65 solutions. It is very clear, both 

 from Cassiopea and Eudendrium, that such changes in the sub-optimum 

 solutions do not and can not alter the essential character of the curves 

 sufficiently to make it analogous with Loeb's. The differences in the 

 behavior of the three organisms is made easier for comparison by table 6, 

 which gives the results of changes in salinity upon the three organisms 

 studied by Loeb and Goldfarb. 



