FIG. 26. Regeneration in Planarians. A, Planaria maculata, normal adult propor- 

 tions; B and C, individuals regenerating after cutting a worm in two at e f in A, 

 scar tissue shown by stippled areas; B' and C/ the same assuming normal pro- 

 portions; D and D', hetereomorphosis in a piece cut from anterior end, a b in A. 

 E, F, G, and H, regeneration of a short transverse segment, c d ef in A, showing 

 regulation of proportions as in B' and C'; I, heteromorphosis in an individual 

 split lengthwise from posterior end. Eyes and pharynx are shown by outlines 

 within the figures; scar tissue by stippled areas. (/ after Morgan.) 



