22 | Ethel Nicholson Browne 
or without the tentacle itself, and by (2) the graft of the material 
of a regenerating hydranth and by (3) the graft of the material 
of a bud. Neither a wound nor the graft of any other kind of 
tissue will stimulate the stock to send out a new hydranth. 
5. Areversal of polarity may take place in a graft, resulting in 
the production of a heteromorphic structure, if the polarity of the 
stock preponderates over that of the graft. 
Zodlogical Laboratory 
Columbia University 
