636 Sergius Morgults 
XXXII and XXXIII are given the data of experiments in which 
were tested solutions containing 95 cc. of sea-water + 5 cc., 
and go cc. of sea-water + 10cc. of a half-molecular solution of 
MeCl.. 
TABLE XXXII 
SEPTEMBER 5 TO 
| NUMBER OF SEGMENTS 
SEPTEMBER I5 (1908) | 
l 
M Mg Cl 5 cc. (xe 14 18 18 19 20| 12] 15 15 16 16) 18] 39 19 a 4 16 = 20] 14) 16) 18 
+95 cc. Sea-w. | New| 4 ‘ 1 4 4 4 4 4 4 4 a 4 5 i 5 5 5 5} 6 6 6 
TABLE XXXIII 
SEPTEMBER § TO 
SEPTEMBER 15 (1908) NUMBER OF SEGMENTS 
M Mg Cle ro cc. f Old aprabe ee 17 | 18 17 | 18 19 14 16 19 | 14 
+ go cc. Sea-w. \ New) 3] 3] 3 4| 4 4 | et 40 5} 5) 5 6 
The beneficial influence which the sea-water slightly concen- 
trated by MgCl, exerted upon the process of regeneration is 
quite obvious not merely from the greater number of regenerated 
segments (Table XXXII) but also from the fact that very few 
worms, as compared with the corresponding control experiment, 
failed to regenerate in sea-water of this concentration. 
Loeb in summing up his interesting chapter—‘Ueber die 
Abhangigkeit der Regeneration bei Tubularia von der Konzen- 
tration des See-wassers”—says: “dass die Wasser-aufnahme 
eine wesentliche Bedingung der Regeneration bei Tubularia (und 
wahrscheinlich bei allen Thieren) ” On the basis of my 
experiments, it would seem scarcely probable that this generaliza- 
tion could be applied to Podarke. On the contrary, the addition 
of an appropriate quantity of MgCl, to the sea-water may accel- 
erate the regenerative process in this animal, while dilution of 
the sea-water may either leave the worms unaffected, or else 
it may impair their regenerative capacity. 
It would, therefore, be legitimate to question whether the accer- 
eration observed in Tubularia is due primarily to osmotic pres- 
