222 MIRIAM F. NUZUM AND HERBERT W. RAND. 



EXPLANATION OF FIGURES. 



1. Diagrammatic cross-section through the brain region of a normal earth- 

 worm. X 50. 



2. Section of mid-dorsal pharynx wall in the brain region of a normal 

 worm. X 250. 



3. Diagrammatic cross-section through the region of the regenerating brain 

 7 days after the operation. The section drawn was not precisely transverse 

 and shows a slightly lateral portion of the brain fundament. X 50. 



4. High-power drawing of that portion of Fig. 3 indicated by X. X 300. 



5. Section through the mid-brain region of a worm at the 1 2-day stage of 

 regeneration, together with the pharynx epithelium lying immediately below 

 that region. X 300. 



6. Diagrammatic cross-section through a worm at the lo-day stage of re- 

 generation. The incision was made in a lateral position (w.). X 40. 



