5o6 C. M. Child. 



Thirty-two days after section : 



A. Both pieces still active and normal in behavior; both are 

 like Fig. 46 in form. The length of the new tissue is much 

 greater than that of the old and the concave outline of the lateral 

 margins is still evident. 



B. As regards behavior this piece is in the same condition as a 

 week ago. Its form is shown in Fig. 47. The relative amount 

 of new tissue has increased somewhat during the week and the 

 pharynx is larger. The great difference in form and structure 

 between the new part of this piece and that of the pieces A both 

 at the present and earlier stages should be noted (compare Fig. 

 47 with Figs. i^J, 40 and 46). The form is widely different from 

 the form of the new part in A at the stage when about the same 

 amount of new tissue is present (Fig. 37). I can conceive of no 

 good reason for this difference except the difference in mechanical 

 conditions to which the corresponding parts have been subjected 

 in A and B in consequence of the difference of motor activity. 

 At the present stage (compare Figs. 46 and 47) the difference in 

 size of pharynx and extent of intestinal branches in A and B is 

 striking. These differences can scarcely be due to anything but 

 differences in functional activity of the parts in the two pieces. 



C. All are dead. 



Of the three remaining pieces B died within the next two days, 

 then one of the two pieces A, and finally the other. 



The history of the series shows very clearly the correlation 

 between activity, capacity for regeneration, and length of life on 

 the one hand and the amount of ganglionic tissue present on the 

 other. Other series of the same sort afforded similar results, 

 though in no case were the differences so well shown in a single 

 series. The questions as to the amount of regeneration, form of 

 the regenerated parts, size of pharynx, and extent of intestine 

 which were discussed in the consideration of posterior regeneration 

 in the absence of the ganglia receive the same answers from this 

 series as from those already considered. The formation of new 

 tissue, but without differentiation in the characteristic manner, 

 in the pieces of the group C is, I think, of especial interest as 

 indicating that the conditions of the two processes are different, 



