384 C. M. Child 



tinal contents have decreased in frequency and strength with the 

 similar decrease in muscular activity. Moreover, the reduction 

 in length of this region has resulted in confining the fluid contents 

 which remain within a smaller space and so in filling this portion 

 of the intestine more completely, since the products of degeneration 

 form more rapidly than they undergo resorption. This pre- 

 pharyngeal region of the body after removal of the head shows 

 little differentiation of function, /. e., the anterior end retains only 

 in slight degree the characteristic motor reactions, hence the func- 

 tional conditions are very similar throughout as regards the intes- 

 tine, so that intestinal reduction shows no marked regional differ- 

 ences. 



In the region posterior to the second pharynx, however, func- 

 tional conditions remain much the same as in the normal animal 

 (Child '05c), for the removal of the head affects the activities of 

 the posterior end but little. Consequently contraction forces the 

 intestinal contents anteriorly until they reach the region of the 

 second pharynx, which they cannot pass, and so are forced into 

 the lateral branches of this region and distend these. The second 

 pharynx appears rather late and before its development the intes- 

 tinal banches just posterior to it often undergo more or less re- 

 duction and after it appears enlarge again, very evidently in 

 response to the altered functional conditions. The movements 

 of the dark substance can be observed very clearly in this part of 

 the intestine and the distension, accompanying contraction of the 

 body, of the lateral branches just posterior to the second pharynx 

 is very evident. 



The fact that the products of degeneration accumulate in the 

 intestine to a much greater extent in headless pieces than in normal 

 animals and pieces with heads is a point of considerable interest. 

 This accumulation cannot be simply the consequence of greater 

 degeneration in these pieces, since in many cases it occurs in stages 

 where degeneration is less advanced than in pieces with heads 

 where no such accumulation exists. In normal animals and pieces 

 with heads these products undoubtedly undergo more rapid resorp- 

 tion than in other pieces and are used to a greater or less extent as 

 nutritive material for other parts, as has already been noted. 



