FORM REGULATION IN CERIANTHUS. 2/1 



The length of the tentacles in the fully distended specimens 

 before section was as follows: marginal tentacles 25-30 mm. ; 

 labial tentacles 1213 mm. 



After section the usual collapse occurred and the tentacles 

 gradually decreased in length. 



October 6. - - 21 days after section. The pieces have remained 

 almost completely collapsed since section. In some instances a 

 part of the body which was more or less completely closed off 

 became slightly distended, but. the frequent examination and 

 removal of slime caused contraction and total collapse. The 

 tentacles were not measured, but marked reduction had occurred 

 during the period of collapse and at this time the tips of all the 

 marginal tentacles were beginning to atrophy. 



October 22.- -37 days after section. Two pieces were lost 

 during the interval. The remaining four pieces were somewhat 

 distended with water but any contraction caused loss of water 

 either in consequence of rupture of new tissue or through one or 

 both of the duplicated aboral pores about which the regenerating 

 muscles had not fully developed. Consequently the internal 

 pressure was still relatively very slight. Extensive atrophy of 

 the distal portion of both marginal and labial tentacles had 

 occurred. The marginal tentacles measured 6-7 mm. -f 12 

 mm. of shrivelled tissue representing the distal portion of the 

 tentacle. The labial tentacles measured 34 mm. -+- I mm. of 

 shrivelled tissue. The basal healthy portions of the tentacles 

 ended bluntly instead of in slender tips as in normal specimens : 

 upon these blunt ends were borne the small shrivelled masses of 

 tissue. 



During the following month the pieces succeeded in closing 

 sufficiently to permit considerable increase of internal pressure 

 and no longer lost water during slight contractions. 



December i . 77 days after section. In three of the pieces 

 the marginal tentacles have increased in length to 10 mm. and 

 the labial tentacles to about 5 mm. 



In the fourth specimen the marginal tentacles were 78 mm. 

 and the labial tentacles about as before. 



In all the atrophied tips have almost completely disappeared, 

 apparently having undergone resorption, but the tentacles are 

 still blunt, not tapering like normal tentacles. 



