No. 6.] REGENERATION IN ANTENNULARIA. 305 



is a factor in the regeneration of this form ; but the development 

 of roots at both ends that first takes place, as I have found, 

 but which Loeb did not observe, and the behavior of pieces 

 attached at one end, as described in the preceding pages, show 

 that the factors determining regeneration are more involved 

 than previous results seem to indicate. 



BKYN MANVR CUI.I.KCK, Feb. 4, 1901. 



