Production of New Hydranths in Hydra 7 
of one or two additional tentacles. In one case two new tentacles 
grew out two days after grafting a tentacle into the circlet, making 
ten tentacles in all (Fig. 16). A week later, three of these became 
fused at the base (Fig. 17). ‘The process of fusion spread until 
the three tentacles formed a single tentacle, leaving eight in the 
circlet, one more than the original number. Unless, however, as 
in this case, an abnormally large number of tentacles was present, 
no later absorption took place after regeneration. 
Series LV Graft Made Below Circlet and Above Middle of Stock 
Result x. In the majority of cases, this graft instigated the 
outgrowth of a new hydranth. ‘The history of these cases is 
similar to that which followed the graft of a tentacle in the middle 
of the body. A double-headed hydranth resulted from the graft, 
but the two heads were considerably shorter in proportion to the 
body than in the case of the middle-region grafts (Fig. 18). 
Result 2. In one case, after a slight outpushing of the body wall 
and the regeneration of two new tentacles (Fig. 19), this new 
hydranth coalesced with the old hydranth a week after grafting 
(Figs. 20, 21). There thus resulted a single-headed hydra with 
an extra number of tentacles. 
Result 3. In another case, no new tentacles were regenerated, 
but the grafted tentacle was included in the old hydranth by the 
shifting downward of the other tentacles (Fig. 22). 
Result 4. In one case, the grafted tentacle was absorbed slowly 
so that after two weeks, no trace of the graft was left. 
Series V Graft Made Between Foot and Middle of Stock 
Result 1. In most cases, this graft followed the same history 
as a foot-region graft. A minute hydra developed from the body 
wall of the stock, and pinched off in three or four days after graft- 
ing, when possessing only one or two tentacles (Fig. 23). 
Result 2. In several cases this graft gave rise to a new hydranth 
similar to that which is found in the middle region. 
Result 3. In one case, the grafted tentacle itself became a small 
new hydranth by enlarging; and on this former tentacle small 
