BROWN: APOGAMY IN PHEGOPTERIS POLYPODIOIDES 2 5 
the unmodified Prantl’s and Knop’s solutions, while only 
dioecious prothallia were observed in the greenhouse cultures 
on the same solutions. In the younger cultures, those not more 
than six or eight weeks old, the majority of the prothallia were 
dioecious, the percentage of monoecious individuals being very 
low even in cultures on the modified solutions. Among older 
prothallia it was not infrequent to find monoecious specimens, 
the antheridia developing on or near the margin of the larger 
heart-shaped prothallia. Antheridia were never observed on the 
cushion, among the archegonia, as is the case in typical monoe- 
cious prothallia. The percentage of male prothallia was much 
higher than that of female, as is usually the case on the modified 
solutions. While many of the male prothallia were mere fila- 
ments of from one to three cells in width bearing antheridia, 
there were also a large number of small irregularly-shaped cell- 
plates one cell in thickness, bearing antheridia over both the 
upper and lower surfaces. The antherozoids in all the cultures 
appeared normal. The majority of the larger prothallia on 
the modifiedsolutions were more or less heart-shaped, without 
a sinus but with a well-developed meristem upon which ar- 
chegonia were formed. Evidently these were not functional, 
as no normal sporophytes developed. In rare cases a few an- 
theridia were formed from the marginal cells of the prothallia 
which developed the apogamous outgrowths and sporophytes. 
DESCRIPTION OF THF APOGAMOUS OUTGROWTHS AND 
SPOROPHYTES 
In the first observed cases of apogamy the prothallia bear- 
ing the apogamous sporophytes were irregularly heart-shaped, 
with a well-developed meristem. Archegonia were formed on 
some of the prothallia, but not antheridia. The apogamous 
sporophytes, in all these cases, originated as slight swellings 
of the archegonial cushion, either on the dorsal or ventral side, 
at some point near the notch or at the center of the cushion. 
These swellings gradually increased in size until dome-shaped 
cellular masses were formed, from which the parts of the 
apogamous sporophytes appeared in the following order: 
leaf or leaves, root, and stem. No foot was formed. In some 
- cases proliferations, either filamentous or slightly expanded at 
the apices, developed from the cellular mass. Also, multicellular 
