vy 



B 



O 



FIG. 80. Regeneration of Planaria maculata. A, normal worm ; B, B 1 , regeneration of 

 anterior half ; C, C 1 , regeneration of posterior half ; D, crosspiece of worm ; D 1 , 

 D 2 , D 3 , D 4 , regeneration of same ; E, old head ; E 1 , E 2 , E 3 , regeneration of same ; F, 

 F 1 , regeneration of new head on posterior end of old head. (From Morgan.) 



