390 C. M. Child 
side of Fig. 8 and in section in Fig. g (it 1s the short tentacle point- 
ing toward the left on the left half of Fig. 9). Why this second 
aboral tentacle should have formed in this case alone it is impos- 
sible to determine, but the fact itself is of interest. “This tentacle 
is formed from tissues which, in other cases have nothing to do 
with tentacle-formation; moreover, its relation to the line of union 
i.e., the original cut surface, is different from that of other tentacles. 
I suggested in an earlier section that the formation of tentacles 
on the aboral side of the line of union in these rings 1s in all cases 
the result of correlation with the tentacle-forming regions on the 
oral side and that suggestion applies to the present case as well as 
to others. Whether the correlation is direct or indirect and what 
its nature may be we cannot now determine. It seems probable, 
however, that it represents some approach to the establishment of 
a new symmetry, or, in other words, where conditions exist which 
determine the formation of one tentacle, they are probably fav- 
orable for the formation of others in a more or less definite arrange- 
ment. This statement does not carry us far toward a solution 
of the problem, but the evidence which these rings afford in favor 
of correlation of some sort in tentacle-formation is at least of 
some value. 
It is perhaps worth while to emphasize the fact that this second 
tentacle on the aboral side appears in a quite different relation to 
the previously existing wound from that in which tentacles usually 
appear. One point in Driesch’s criticism (Driesch ’05, p. 776) 
of my earlier work on Cerianthus was to the effect that I ascribed 
no localizing influence to the wound. While this criticism was 
not correct, the fact that the relation of tentacles to the region of the 
wound may differ under different conditions is nevertheless im- 
portant since it constitutes positive evidence. And this fact is, 
I believe, established by the case described above. 
III CONCLUSION AND SUMMARY 
The phenomena of regulation in these rings are of considerable 
interest, not as “abnormalities” or “errors in regulation”’ but as 
reactions under conditions different from those usually present. 
