564 



S. M or or nil 



weeks, i.e., no new segments had regenerated posteriorly. The 

 regenerated segments, however, grew larger, and all the microscop- 

 ical ones at the tip of the tail became conspicuous, and their setae 

 of considerable size. Slight differences in both these tables (VII 

 and VIII) are probably due to some miscounts, w^hich are almost 

 inevitable. 



TABLE VII 



November 2g, igoO/ December 2g, igo6 



Let us now consider this last experiment in connection with the 

 previous one, and see what we can infer from them. In either 

 case the pieces of the w^orms were regenerating without food for a 

 period of six weeks. In the latter case, where the process was 



