144 c - M - CHILD. 



Delay or prevention of closure was accomplished by various 

 other methods and since the results in all cases agree with those 

 of the series already described an account of all experiments 

 along this line would be merely a multiplication of detail to little 

 purpose. A summary of the principal other methods employed 

 and the results obtained will be sufficient. 



Series j i. 



September 28. Seven specimens were cut transversely aboral 

 to the aesophagus as in Fig. 8 and then slit longitudinally down 

 one side for three fourths of their length, differing from Fig. 8 

 in that the longitudinal cut did not extend all the way to the 

 aboral end. These pieces closed much more readily than those 

 of Series 11, 17 and 28. In this series as in Series 28 some of 

 the pieces closed and became distended much sooner than 

 others. The earliest distension of the body and elongation of 

 tentacles occurred 14 days after section. Thirty-eight days after 

 section all of the pieces were completely closed and with mar- 

 ginal tentacles more than 5 mm. in length. The delay in closure 

 was not as great in most cases as in Series 28, but the results as 

 regards delay in tentacle-regeneration agree in all respects with 

 those of that series. 



In two series 18 and 20 8 and 6 pieces respectively were 

 separated by a transverse cut aboral to the oesophagus as in 

 Fig. 7, and then the oral half of the piece was split into two 

 parts by a longitudinal cut through both sides of the body. In 

 consequence of this cut the oral part of the piece was doubled, 

 the aboral remained single. In a few cases specimens with 

 double oral ends and separate sets of tentacles resulted, but the 

 more common results were the separation from the piece of the 

 divided parts at its aboral end or the union of the two to form an 

 individual essentially normal. 



It will be evident at once, however, that the inrolling after 

 such an operation must have been rather complex. Closure of 

 the openings by new tissue was usually slow whatever the par- 

 ticular result, and delay in the regeneration of the tentacles oc- 

 cured here in the same manner as in the series alaeady described. 

 The " double-headed ' specimens will be described in another 

 connection. 



