66 C. M. Child 
the wound. Longer pieces—e. g., distal to the line 4 or between 
the lines a and 4 in Fig. 1—may live for several weeks and in such 
pieces tentacles very often appear at the aboral end. 
Fig. 1 Diagrammatic outline of Harenactis, indicating levels of section. 
But partial isolation of some portion of the cesophageal region 
by a lateral incision extending only part way through the body 
is a more satisfactory method for the production of heteromorphic 
tentacles than complete isolation. After partial isolation the 
part in question lives indefinitely and in every case that I have 
observed gives rise to heteromorphic tentacles. For convenience 
the two methods and their results are considered separately. 
