Factors m Regeneration 35 1 



No. of branches 

 719 



The more concentrated the sea-water the fewer the polyps pro- 

 duced. SHght increase of concentration results in large decrease 

 in the number regenerated. The maximum concentration beyond 

 which no regeneration occurs is about 77 per cent. Retardation 

 observed in diluted sea-water likewise takes place in concen- 

 trated solutions. It is almost needless to add that the greater the 

 concentration the slower as well as the fewer the polyps produced. 



Experiment ^2. The maximum concentration at which regen- 

 eration of Eudendrium stems will take place was more definitely 

 ascertained by transferring them daily to solutions more concen- 

 trated by about i\ per cent. Regeneration occurred in all con- 

 centrations from norm to 57^ per cent. Even in 50 per cent 

 solutions, shoots wxre observed. Thus by slowly increasing the 

 concentration of sea-water, stems were made to regenerate polyps 

 in a considerably greater concentration than had otherwise 

 taken place, when stems were placed at once into the 57^ per cent 

 concentrated solution. 



Experiment ^j. Stems that had been kept in concentrated solu- 

 tions were after 18 days transferred to normal sea-water. 



TABLE 25 



Stems kept in concentrated solution i8 days were transferred to normal sea-water. On the fol- 

 1 iwing days there regenerated: 



Previous 



Concentration 2d 3d 4th 5th 6th 7th 8th 9th loth 



Norm 0% 0% 2% 2% 4% 4% 6% 6% 10% 



95% 2 2 224241128 



89% o i 3 3 7 12 16 26 35 



79% o o 0000000 



73% O PPOQQOO 



