ETTER: POLYEMBRYONY IN POLYPODIACEOUS FERNS 103 
lost. In every instance the severed halves either developed an 
embryo-sporophyte within six to ten days or regeneration began. 
The regenerated part was always more vigorous than the part 
from which it came. In as much as the regenerated parts always 
became monoecious, water was added from time to time to the 
individual prothallia, and there were permitted to dry somewhat 
each time before watering, in order to insure fecundation. 
TEXT FIG. 3 shows two independent sporophytes which 
developed on the archegonial cushion of a regenerated lobe. 
The old lobe is shown at a. 
It is interesting to note that 
the regenerated lobe is larger 
and much more vigorous than 
the older one. e new 
lobe did not produce an 
apical sinus in this instance, 
although a well-formed arch- 
egonial cushion occupied a 
considerable portion of its 
extent. 
The fact that at least 
three sporophytes may be 
induced to develop to inde- 
pendent existence from a 
single lobeis well illustrated 
in TEXT FIG. 4. The origi- 
nal lobe, from which the new Fic. 5. A typical result obtained 
one came, was absorbed, and y dividing a gametophyte of Matteuccia 
. : Struthiopteris into longitudinal halves. 
this very vigorous new lobe A, two sporophytes on one regenerated 
grew to a width of 10 mm. prothallium, e; a, the older sporophyte; 
without forming a sinus, 6, the younger sporophyte; d, the old 
before asporophyte, a, ap- 
peared, fifty-four days after 
the dividing of the original 
gametophyte. Twenty-six 
days later another sporophyte, b, came near the first. After a 
lapse of twenty-nine days morea thirdsporophyte, c,came. The 
first and the second sporophytes grew as well as one should 
expect, while the third grew very slowly but otherwise normally. 
All three of them would doubtless have become independent 
sporophytes. 
other half, f, of the original prothallium 
upon which a sporophyte, ¢, soon be 
to develop. 
