568 



S. Morcriilts 



In the tables given below are recorded the number of segments 

 present in the anterior pieces left after the operation of November 

 14 {c) and the number of new segments they had produced at the 

 end of two weeks, November 28. 



In accordance with our method of calculating the average num- 

 ber of new segments per one old segment, to define the regenerative 

 dower, we will have o.i i segments standing for this power in pieces 

 from A and 0.06 segments for that in pieces from B. 



TABLE IX 



November 1 4/ N ovemher 28 



Anterior parts from worms formed 

 by regeneration of B 



No. of old seg- No. of new seg- 



ments ments 



20.5 



1-3 



Average No. of new segments 

 per one old segment, o .06 



20.4 2.3 



Average No. of new segments 



per one old segment, o . 1 1 



* Whenever the term "bud" is used, it indicates that an unsegmented portion in which the anus lies 

 is produced only, but no segments are deposited between this regenerated organ and the old tissue. 



Of course these data are so meager that it would hardly justify 

 much speculation, but it seems to me nevertheless very suggestive. 

 If we compare the rate of posterior regeneration in the little worms 

 formed from the anterior parts of the regenerated tail pieces (A and 

 B), we find that they stand to each other in a ratio very much like 

 that of the rate of posterior regeneration in the old parts, from 

 which the A and B tails originate. 



