98 STEIL: SOME NEW CASES OF APOGAMY IN FERNS 
Sw. (A. Filix-mas cristatum’’). In the former Miss Allen (1911) 
described nuclear and cell fusions in the sporangia, previous to the 
formation of the spores. Kny (1895) discovered apogamy in an un- 
crested form of A. Filix-mas (‘‘A. Filix-mas genuinum”’). Lang 
(1898) found apogamy in the aberrant varieties of A. Filix-mas: 
known as ‘‘ Nephrodium pseudo-mas var. polydactylum Wills”’ and 
N. pseudo-mas var. polydactylum Dadds.”’ In these same varieties 
(discussed under the name ‘‘ Lastrea pseudo-mas var. polydactyla’’), 
Farmer, Moore and Digby (1903) and Farmer and Digby (1907) 
described remarkable nuclear fusions in the prothallium before 
the formation of the apogamous embryos. In a preliminary note 
on apospory Miss Digby (1905) had already reported apogamy in 
“ Lastrea pseudo-mas var. cristata apospora Druery.”’ 
Heilbron (1901) found apogamy in Aspidium aculeatum (L.) 
Sw. var. cruciato-polydactylum Jones and A. angulare Willd. 
forma grandidens Moore. Five years later (Steil, 1915 a and d) 
apogamy was reported in A. hirtipes Bl. (Nephrodium hirtipes 
Hook.), A. Tsus-Simense Hook. and A. chrysolobum Kaulf. 
(Lastrea chrysoloba Presl). Apogamy has also been discovered 
as a result of the investigations herein described in A. varium 
(L.) Sw., A. auriculatum (L.) Sw., A. caryotideum Wallich, Cyr- 
tomium Fortunei J. Sm. and C. Rochfordianum Hort.* 
THE DEVELOPMENT OF THE PROTHALLIA AND SEX ORGANS 
In all the species so far studied, the prothallia become typically 
heart-shaped. Between the prothallia of apogamous and non- 
apogamous species no difference was noted excepting that in the 
latter tracheids sometimes appear. The prothallia of all the 
species of Aspidium in which apogamy has been discovered bear 
glandular hairs on both surfaces and on the margins (PLATE 4, 
FIGS. I, 2,and 5; PLATE 5, FIGS. 20 and 21), while in both Pellaea 
(PLATE 5, FIGS. 13, 14, and 15) and Pteris (PLATE 4, FIGS. 3, 4, 
and 6) such hairs are always absent. The prothallia in Aspidium 
grow to a much larger size than in Pellaea and in most species 
* Benedict (Bailey’s Stand. Cycl. Hort. 2852. 1016) gives C. ca 
asasynonym of C. falcatum J. Sm. (= A. falcatum Sw.); Christensen (Ind. F 1. 460. 
1916) includes both A. caryotideum and Cyrtomium Fortunei among the synonyms of 
the same species. 
