Brown: APOGAMY IN PHEGOPTERIS POLYPODIOIDES 19 
Nagai (’14), describes cases of apogamy on prothallia of 
Asplenium Nidus grown on agar-agar and on filter paper saturat- 
ed with nutrient solutions. These cultures were kept somewhat 
dry, in bright light, and at room temperature. The occurrence 
of apogamous sporophytes is also described on prothallia which, 
after growing on nitrogen- and phosphorus-free nutrient solu- 
tion, had been transferred to sand saturated with nitrogen-free 
nutrient solution and left in bright light and at higher tem- 
perature. He does not attribute the development of these 
apogamous outgrowths to dryness but to unfavorable or un- 
known internal physiological conditions. 
Stokey (’18) reports a case of apogamy in the genus Dicksonia 
and a few cases in the genus Cyathea. These occurred in cultures 
which had been exposed to rather intense light and grown on a 
medium of moist peat. While she does not consider dryness to 
be the determining factor, and while she does not state definitely 
that the intense light was the stimulus, she is of the opinion 
that the determining factor in one case of apogamy is not 
necessarily the determining one in another. 
Steil (718) found apogamy occurring in the genera Pellaea, 
Pieris, and Aspidium, in cultures on nutrient solution, sphagnum, 
nutrient agar, peat, clay, and loam, which were kept under bell 
jars in a Wardian case in the greenhouse. He does not consider 
the cultural conditions as the factor which induces apogamy in 
any of these cases. 
MATERIAL 
While collecting fern spores in and about Ithaca, New York, 
during the summer of 1915, my attention was called to a sporo- 
phyte of Phegopteris polypodioides Fée growing on a lawn in the 
city. It had been transplanted from its native habitat and did not 
appear normal or healthy, owing, doubtless, to the unfavorable 
conditions under which it was growing. As there was only one 
fertile frond, and this a small one, few spores were obtained. 
Cultures were made from these spores in the early fall upon 
Prantl’s and Knop’s full nutrient solutions and on certain 
modifications of these solutions. After the spores were sown 
the cultures were placed before an east window where condi- 
tions of light and temperature were approximately uniform for 
all. Once each week the prothallia were transferred to fresh 
