REORGANIZATION 93 



not resorbed but simply rises and flattens out to the level of the 

 adoral field with whose stripes its own are continuous. As the 

 primordium migrates forward and carries with it some ecto- 

 plasmic striping to the right, new and old frontal-field stripes are 

 brought together, but though homopolar they do not join. Instead, 

 the anterior ends of the new stripes are pulled over to the point 

 where the old mouthparts dissolved and the resulting frontal field 

 therefore shows two swirls of striping (Fig. 2i).This doubleness 

 is an enduring character which identifies stentors that have under- 

 gone reorganization, a sign which is often useful in following the 

 performance of experimental animals. Sometimes one finds 

 stentors with three disjunctive systems of striping in the frontal 

 field, indicating that these animals have twice reorganized, though 

 they may be proters from an ensuing division. 



Fig. 21 . Anterior end view of a coeruleus which had reorganized 

 twice, showing muhiple pattern of frontal field. 



After the reorganization primordium is nearing completion, 

 a secondary stripe multiplication occurs just below the newly- 

 forming oral region quite as in the opjsthe of dividers, as pointed 

 out by Schwartz. This stripe increase will form a new ramifying 

 zone and completes the reorganization process. It now remains to 

 report what has been done toward analyzing the sequential events 

 in reorganization and above all to inquire into its possible signifi- 

 cance for the life of the organism. 



