110 



C. M. CHILD 



head-frequency in a, shows but Httle effect in h, while in c it shifts 

 head-frequency upward to a considerable extent. In contrast 

 to this the same concentration in III acting throughout recon- 

 stitution brings about a very great downward shift in a, less in h, 

 while in c there is if anything a slight upward shift. The long 

 period in KCN shows a greater downward shift in a and a lesser 



TABLE 3 



Series 489. Worms 18-20 mm., in laboratory six months before experiment: I. Con- 

 trol in u'uter; II. Whole worjus in KCN m/ 200000 immediately before section, 

 pieces xuere cut and kept in the same concentration during reconstitution with 

 renewal every forty-eight hours; III. Pieces cut in ivater, in KCN m/200000 

 forty-five minutes — one hour and forty-five mimites after section and kept in the 

 same concentration during reconstitution with renewal every forty-eight hours 



TABLE 4 



Series 4o7. Worms 18 mm., in laboratory two months before experiment: I. Control 

 in ivater; II. After all pieces cut placed in KCN m/200000 for twenty-four hours; 

 III. After all pieces cut placed in KCN m/200000 for twenty days. 



