Production of New Hydranths in Hydra a7 
ity. This conclusion agrees with that of Miss King who, in similar 
experiments used hydras of different shades of green as stock and 
graft. 
Group D 
Graft of Green Foot in White Hydra 
In four out of five cases in which the lower half of a hydra was 
grafted by its cut oral surface into the middle region of a normal 
hydra, the grafted foot was absorbed. The history of the other 
case was as follows: On February 22, a green hydra was cut 
in two, and the posterior half was grafted by its oral surface into 
the middle of the body of a white hydra. On February 25, the 
graft had moved down somewhat toward the foot of the stock (Fig. 
55). On February 27 a new head was evidently being formed at 
the union of graft and stock, of graft material (Fig. 56). On 
February 28 the graft had quite completed itself, having formed 
several tentacles, but was still attached near the foot region to the 
stock (Fig. 47). On February 29, the green hydranth including 
part of the grafted foot and the regenerated head separated off 
from the white hydra, leaving, however, a small amount of green 
foot tissue attached to the stock (Fig. 57). 
From these experiments I should conclude that if the graft asserts 
itself sufficiently not to be absorbed by the stock, it maintains its 
individuality, forms its own tentacles and separates off as a com- 
plete hydra. 
Group E 
Reversed Polarity in Green and White Grafts 
Cases of heteromorphosis in hydra produced by grafting have 
been reported by Wetzel, Peebles,and King. A heteromorphic foot 
has been produced by Wetzel by removing the foot ends of the 
two hydras, grafting the two aboral ends together and cutting off 
one head close to the tentacles. A normal hydra was produced 
with a foot at the former oral end. Peebles performed the reverse 
experiment, cutting off the heads of two hydras, grafting them 
together by their oral surfaces and subsequently cutting off one 
