Studies oil Regulation 



3^. 



drawn in Fig. i, so that the difterence in size of the piece in 

 Figs. I and 13 is not wholly due to reduction. Fig. 13 repre- 

 sents a stage 143 days after section. Comparison with Fig. 6, 

 a normal specimen kept for about the same length of time without 

 food shows that reduction is somewhat more advanced in the head- 

 less piece than m the normal animal. In such pieces, however, 

 the axial intestine, especially in the prepharyngeal region, appears 

 to be more or less distended by the dark colored products of degen- 



^S 



Figs, f^ axd 14 



eration whose movements can readily be followed. This sub- 

 stance accumulates in headless pieces to a greater extent than in 

 pieces with heads, undoubtedly because of the fact that these 

 pieces, being less active than normal animals and pieces with 

 heads, require less nutritive material and so do not use up the prod- 

 ucts of intestinal degeneration as rapidly as do the other pieces. 

 Consequently the products accumulate in the intestine and, since 

 the movements do not force the intestinal contents into the lateral 



