Production of New Hydranths in Hydra mp 
stock, there grew out a minute hydra, similar in formation and 
appearance to that instigated by a graft of a tentacle and basal 
tissue into the foot (Figs. 38, 39). 
Result 2. In the other case, the tissue was absorbed and no 
regeneration took place. 
CONCLUSION 
This group of experiments shows that the whole tentacle is not 
necessary for the production of a new hydranth on the part of the 
stock. But merely the peristome tissue at the base of the tentacle 
is sufficient, when grafted, to instigate the outgrowth of a new 
hydranth. 
Group E 
Tissue Anterior to Circlet of Tentacles as Graft 
The amount of tissue anterior to the circlet of tentacles is very 
small and it was found very difficult to cutit off without getting into 
the region of the tentacles. By waiting, however, until a large 
hydra was fully expanded and very quickly bringing the scalpel 
just anterior to the tentacles, I found it possible in five cases to get 
this small bit of tissue cut off. This was grafted into the middle 
region of the stock. 
In none of the five cases was any regeneration instigated. ‘The 
grafted tissue was absorbed, so that the day after grafting no 
trace of the graft was to be seen. 
The tissue anterior to the circlet of tentacles will not give the 
stimulus necessary for the outgrowth of a new hydranth, when 
grafted into the body wall of a stock hydra. 
Group F 
Tissue From other Regions of the Body as Graft 
In this set of experiments, I endeavored to find out whether 
tissue from any region of the body other than at the base of the 
tentacle, would, when grafted, give rise to a new hydranth. For 
