ORGANIZATION AND GRowTH 233 
TABLE III 
3.8% 
5.1% 4.87 oe ted 4.1% | (Normal | 3.2% 2.5% Le 1.6% 1.3% 
Sea-Wat'r) 
mm, mm. mim. mm. mm mm. mm mm, mm, mm, 
1 2 3 1 10 13 19 5 1 0 
1 2 4 5 5 7 13 5 0.5 0 
0.5 3 2 3 5 6 8 4 0.6 0 
0 1 3.5 2 6 1 7 3 0 0 
0 1 2 3 3 5 11 5 0 0 
0 0 6 3 2 5 12 3.5 0 0 
0 0 2 3 4 5 4 & Ee 0 
as 0 r 4 0 0 2 i 
Av...0.3 1.1 a2 3.8 4.4 6 | 10.6 4.4 0.3 0 
We obtain a better view of these results when we present 
them graphically. In the curve shown in Fig. 60 of the text 
the different amounts of salt contained in each 100 c.c. of the 
(é) z 2 3 4 5 6 
FIG. 60 
various solutions are represented on the axis of abscissas, 
the increase in the length of the animals on the ordinates. 
We see that the growth is nil in a 1.3 per cent. salt solution; 
that it is Just perceptible in a 1.6 per cent. solution; that it 
increases very rapidly with an increase in the concentration, 
attaining a maximum in a 2.5 per cent. solution, and then 
decreases slowly with a further increase in the concentration. 
Maximal linear growth does not occur in ordinary sea-water, 
but in markedly diluted sea-water. The meaning of the 
curve is very simple: the cells of Tubularia must be turgid 
in order to grow, and this is possible only as long as the 
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