THE RANGE OF DOMINANCE 



143 



basal structures develop on the lower side of the piece in 

 contact with the underlying surface, and gradually the 

 piece is transformed into a new small individual (Fig. 74) . 

 In most cases the old outline of the piece is still pre- 

 served by a thin layer of hardened slime secreted by the 

 piece while in alcohol. This is indicated by the dotted 

 line in Fig. 74. Susceptibility determinations show 



Figs. 71-74. — Experimental establishment of a new major axis in a 

 piece of Corymorpha: Fig. 71, the piece after section; Fig. 72, after 

 reduction in alcohol; Fig. 73, appearance of new hydranth on upper 

 side after return to water; Fig. 74, fully developed new individual; 

 dotted lines indicate old outline of piece preserved by slime. 



that in alcohol the original axial gradient disappears, 

 and that when the pieces are returned to water a new 

 gradient arises in the direction in which the new axis 

 develops. Since the pieces adhere to the surface soon 

 after being placed in alcohol, it is possible to keep them 

 in the same position throughout the experiment and so 

 to be certain of the original direction of the major axis 

 and gradient, even though they become hemispherical 



