FORM REGULATION IN CERIANTHUS /KSTUAKII. 



47 



parts, hence it contracts and the other parts are pressed against 

 it, permitting union of the cut margins to occur. 



In several cases of this sort the incisions were reopened one or 

 more times after they had healed in the manner above described, 

 a in one case tentacles were produced, but later disappeared. 

 The history of this case is briefly given since it presents some 

 features of importance. 



September I . — Very oblique incision directed orally. 



September g. — Almost entirely healed ; reopened. 



Marginal tentacles on original disc 12-15 ni^n. in length except 



Series ji 



20 



21 



above cut, where they are reduced to about i mm. Labial ten- 

 tacles 3-4 mm., except over cut, where 1-2 mm. 



September 28. — (Fig. 2 1 .) Marginal tentacles on original disc 

 10-12 mm. in length except over cut, where they are reduced to 

 about I mm. Labial tentacles 2-3 mm., except over cut, where 

 they are scarcely visible. 



The lateral wound is closed by thin new tissue, but near its 

 distal end two small tentacles appear, one arising from each side 

 of the cut. Proximal to the tentacles the cut margins have united 

 longitudinally and distal to the tentacles a broader area of new 

 tissue fills in the space between the old margins. The course of 

 the septa is indicated by the dotted lines in Fig. 21. It is evident 



