Production of New Hydranths in Hydra 5 
other three tentacles were absorbed one by one, while the bud was 
developing, until on March 12, three weeks after grafting, the whole 
regenerated material had been absorbed and the bud had pinched 
off leaving the stock as a normal hydra. 
The departure from the usual result may be accounted for in this 
case by the formation of the bud. It may be that the stimulus for 
regeneration was present and excited the growth of new tissue 
as is evidenced in the outgrowth of three new tentacles, but when 
the bud developed, the available material was used for its develop- 
ment, thus depriving the regenerating hydranth of any means of 
growth. 
Result 3. In only two instances, no regeneration was stimulated 
by the graft of a tentacle with its basal tissue into the side of the 
stock hydra. But a gradual process of absorption set in, so that 
after two weeks no trace of the tentacle was left. It is possible 
that this result was due to the fact that none of the peristome tissue 
was left at the base of the tentacle, this bit of tissue being accident- 
ally broken off from the tentacle in the process of grafting; or, the 
results obtained in these two instances may have been an exception 
to the usual result. 
Series II Graft Made in Foot of Stock 
Result tr. The usual result following grafting a tentacle with 
a small bit of peristome tissue at its base into, or in the region of, 
the foot of a normal hydra, was the outgrowth of a diminutive 
hydra at the point of grafting. ‘The grafted tentacle was partially 
absorbed as regeneration took place, till it assumed the proportion 
proper for the small hydra. ‘This small hydra pinched off from 
the stock in three or four days after grafting, sometimes with only 
the grafted tentacle present, sometimes with one or two regener- 
ated ones. 
Following the history of one of these grafts, we find it as follows: 
On March 5, I inserted a tentacle with a bit of peristome tissue at 
its base into the foot of a normal green hydra (Fig. 9). On the 
next day, there was a very slight outpushing of the body wall of 
the stock carrying the grafted tentacle with it. On March 7, this 
