50 C. M. CHILD. 



consciously closing the artificial openings. In the following 

 paragraphs the principal forms of inrolling in the cut pieces are 

 described. 



The case of the closure of the ends of a cylindrical piece which 

 was described in the first paper is the simplest of all. Collapse 

 occurs with the escape of the water from the enteron and within 



FIG. 2. 



FIG. 6. 



FIG. i. 



FIG. 4. 



FIG. 8. 



FIG. i. 



FIG. 7. 



FIG. 9. 



a few moments the cut ends begin to bend inward and finally 

 close the openings except for the small slits between the folds. 

 The diagrams, Figs. I, 1 2 and 3, illustrate this case, Fig. I repre- 

 senting the cylindrical piece at the time of section, Fig. 2 the 

 longitudinal section of the ends after the bending in of the cut 

 margins, and Fig. 3 a transverse section, indicating the flattening 



1 The diagrams representing the inrolling are much less highly magnified than pre- 

 ceding figures. 



