2O8 C. M. CHILD. 



bases leaving stumps i mm. or less in length. Then a second 

 cut was made through the ossophageal region near its aboral 

 end. In the distal pieces thus formed the oesophagus extends 

 from end to end of the piece, cut surfaces being present at each 

 end (Fig. 15). 



October i. 3 days after section. In all cases the cut mar- 

 gins of ossophagus and body-wall have united both orally and 

 aborally in the same manner as in Fig. 8. All pieces are more 

 or less distended and the oral margins slightly crenated in corre- 

 spondence with the intermesenterial chambers. 



October 4.. 6 days after section. All pieces with marginal 

 tentacles, varying in length in different pieces from mere buds 

 just visible to 2 mm. : labial tentacles still short stumps. 



October 7. 9 days after section. In two pieces the aboral 

 end has closed as in Figures 1214: these pieces fully distended ; 

 one with marginal tentacles 5 mm. ; labial tentacles about 2 mm.; 

 the other with marginal tentacles 3mm., labial tentacles 1 1.5 mm. 



In the five remaining pieces no aboral closure has occurred ; 

 the distension has decreased ; the marginal tentacles have in- 

 creased in length, though very slightly, since the previous exami- 

 nation, varying from minute buds to 1-2 mm. 



October 75. 1 7 days after section. One of the pieces which 

 closed aborally with marginal tentacles 8 10 mm., labial tenta- 

 cles 5-6 mm. At aboral end new tissue 1-2 mm. 



The other closed piece was lost. 



In none of the five remaining pieces has tentacle-regeneration 

 proceeded since the previous examination. All appear almost 

 completely collapsed and the tentacles are reduced to mere buds 

 in all, being scarcely visible in some. One piece has begun to 

 break up. 



During the following two weeks the five pieces which did not 

 close broke up into small pieces and died, a frequent occurrence 

 in small pieces in which closure and regeneration do not occur. 

 The one closed piece remained in good condition. 



The difference between the piece that closed and the other five 

 is striking. None of these five pieces ever regenerated marginal 

 tentacles more than 1-2 mm. in length, and practically no re- 

 generation of labial tentacles occurred. Yet the one piece which 



