48 o C. M. Child. 



In Figs. 9 and lo the condition of the pieces of Series 73 

 thirty-eight days after section is indicated. In one of the pieces 

 the new tissue showed the tapering form of Fig. 10, the other 

 pieces resembhng Fig. 9. The former piece was capable of 

 more rapid locomotion than the others. In all the pharynx and 

 genital area are visible and an axial intestine with short branches 

 extends down the middle of the pieces. 



The condition of the pieces of Series 82 thirty-four days after 

 section is indicated in Fig. 11. Different pieces differed 

 slightly as regards the length of the new tissue, but other differ- 

 ences were not observed. Pharynx and genital area were present 

 and the new tissue was well-filled with intestinal branches. 



The pieces of Series 82 differ markedly, however, from those of 

 Series 73 in that the amount of regeneration is much greater in the 

 Series 82, where the cephalic ganglia are present. Moreover, 

 comparison of the Figs. 9 and 10 with Fig. 11 shows that the 

 pharynx is longer and the intestinal branches much more abun- 

 dant in Series 82. 



After this time there was no further advance in regeneration. 

 The pieces of both series had already begun to decrease in size 

 and continued to do so, but the decrease was somewhat more rapid 

 in Series 82 than in Series 73. 



In these two series the differences seem to be wholly quantita- 

 tive. The pieces in which the cephalic ganglia are intact regen- 

 erate more rapidly, at least in the later stages; the amount of new 

 tissue formed is greater; the pharynx is larger; and the intestinal 

 branches are more numerous. 



Series 78. Five specimens were cut transversely through the 

 middle of the pharynx (Fig. 12) the anterior part with head and 

 cephalic ganglia intact being used. 



Series 79. Five specimens were cut at the same level as in 

 Series 78 but in these the head was removed by a second cut just 

 posterior to the ganglia (Fig. 12). 



Figs. 13 and 14 indicate the condition of the posterior ends in 

 the two series fourteen days after section. In Fig. 14 (Series 79, 

 without cephalic ganglia) the contraction of the cut surface is 

 greater and the new tissue contains fewer intestinal branches 



