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 



It is self-evident that FIG. 02 



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 each vessel always amounted to exactly 300 c.c. 



