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 oldstems. O re- 
mained in sea-water to 
which 0.3 per cent. KCl 
was added. At the oral 
end 6 a deformed polyp C 
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. 68 
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. 
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