Stiuhi's on Regulation 373 



Intestinal reduction in other portions of the body goes on in the 

 same manner as in normal animals, though somewhat more 

 rapidly. But, meanwhile, short and slender new lateral branches 

 develop on the postpharyngeal intestine in many cases. These 

 never attained full development in the specimens observed, but 

 there is no doubt that if the animals had been fed they would have 

 developed and reached normal conditions. Fig. 9 shows the con- 

 dition seventy days after section of the piece from which Figs. 

 7 and 8 were drawn. Intestinal reduction in the pharyngeal and 

 prepharyngeal regions has followed the typical course but in the 

 postpharyngeal region new branches have developed. 



In still later stages without food reduction of all parts of the 

 intestine takes place almost equally until only very short lateral 

 branches remain (Fig. 10, 143 days after section). How much 

 longer such pieces may live it is impossible to say, for my observa- 

 tions extended over only 143 days and many pieces were alive 

 and active at the end of this time. 



In shorter pieces the process is essentially the same. Taking, 

 for example, a piece including that part of the body anterior to 

 the line b in Fig. i, the new postpharyngeal region is short, and 

 the pharynx appears nearer the posterior end and the amount of 

 regeneration is somewhat greater than in a long piece like the pre- 

 ceding. Fig. II shows this piece fifteen days after section. All 

 traces ot the postpharyngeal lateral intestinal branches have dis- 

 appeared, only a very slender axial intestine remaining, which, 

 however, extends a short distance into the regenerated tip. In 

 the short pieces degeneration may begin in the redifferentiating 

 region within four days after section, but in the long pieces does 

 not usually appear for a week or more. As regards later stages a 

 similar difference exists. 



In these short pieces intestinal reduction in other regions is 

 always much more rapid than in longer pieces. In Fig. 11, for 

 example, a stage fifteen days after section, reduction is far 

 advanced in the pharyngeal and prepharyngeal regions, and in 

 Fig. 12, forty-five days after section, scarcely any traces of lateral 

 branches exist in any part of the intestine. These short pieces 

 usually die from forty to sixty days after section, /. e., much 



