Studies on Regulation. IV. 



113 



I. August 31, 1903. A specimen of average size was prepared 

 as shown In Figure 10. The greater part of the body was re- 

 moved by a transverse cut about 2 mm. posterior to the cephalic 

 gangha and the anterior piece thus obtained was split longitudin- 

 ally. In this case the longitudinal cut appeared to be coincident 

 with the median plane, but the differences In behavior of the two 

 pieces after section Indicated that the left cephalic ganglion was 

 injured to a greater extent than the right. After section the cut 



Fig. 10. Fig, 11. 



Fig. 13. 



Fig. 16. 



Fie- 15. 



Fig. 17. 



Fig. 18. 



surfaces soon contracted thus bending each piece Into a curved 

 form resembling Figure 9 and In both pieces locomotion diverged 

 constantly toward the cut side, the pieces thus moving in circles, 

 as Indicated by the arrows accompanying the figures. 



September 3: 3 days after section: 



The pieces have assumed the forms shown In Figures 1 1 and 

 12. New tissue has appeared almost uniformly over the whole 

 extent of the cut surface. The left plecp (Figure 12) is consid- 

 erably more contracted than the right piece (Fig. 11) and moves 



