CERTAIN GENERAL CHARACTERISTICS 



SI 



of the distal part removed occurs as indicated in Figure 24, A and B. If 

 the plane of section is strongly oblique to the longitudinal axis (Fig. 23, 

 FF), reconstitution occurs most rapidly on the most distal part, and the 

 rate decreases proximally until at the most proximal levels nothing more 

 than wound-healing may occur (Fig. 24, C). If the oblique section is made 

 so that one or two of the original marginal organs remain (Fig. 23, GG), 

 reconstitution of marginal structures may be largely or even com- 



LA 



A 



D 



Fig. 24, A-D. — Reconstitution in Haliclystus. A, early stage after transverse section at 

 levels BB or CC of Fig. 23; B, advanced stage after section at level EE of Fig. 23; C, early 

 stage after obliciue section with removal of all marginal organs; D, reconstitution after oblique 

 section leaving small part of original margin (from Child, 1933&). 



pletely inhibited (Fig. 24, D). Later removal of the original marginal 

 parts, even after a week or two, is followed by development of at least 

 some of the marginal structures previously inhibited. When only a small 

 part of the marginal region is removed, as indicated by A'A'^ and YY in 

 Figure 23, little or no development of the parts removed occurs (Child, 



1933^)- 



After oblique section of the scyphistoma of Aurelia the rate of recon- 

 stitution decreases from distal to proximal levels of the oblique surface, as 

 in Haliclystus. Tentacles from the most distal level attain full length in a 



