ORGANIZATION AND GROWTH 



247 



equal to that of the old. Fig. B remained in sea-water to 

 which 1.3 per cent, NaCl was added. Frail polyps have 

 formed at each end with only four to six tentacles. The 

 growth is practically zero, and the diameter of the newly 

 grown parts is much less than that of the old stems. C re- 

 mained in sea-water to 

 which 0.3 per cent. KC1 

 was added. At the oral 

 end b a deformed polyp 

 without tentacles has been 

 formed, while no growth 

 whatsoever has taken place. 

 The drawing has been 

 somewhat enlarged, and 

 the piece ab of Fig. A is 

 not shown in full length in 

 order to save room; it was 

 in reality as long as that 

 shown in Figs. B and C. 



XIV. THE RELATION OF RE- 

 GENERATION AND GROWTH 

 TO THE QUANTITY OF SEA- 

 WATER 



FIG. :;i 



It is self-evident that 

 for the regeneration and 



growth of Tubularian stems the quantity of sea- water is of 

 importance only in so far as it enables the stems to obtain 

 from it a sufficient amount of the inorganic substances 

 necessary for regeneration and growth. As soon as this is 

 the case, variations in the amount of sea-water should have 

 no effect upon these processes. 



In the experiments detailed thus far the amount of water 

 contained in cadi vessel always amounted to exactly ^00 c.c. 



