Steil. — Apogamy in Nefi hr odium hirtipes , Hk, 1 1 1 
In all the ferns which Lang placed under these cultural conditions, 
excepting Aspidium angular e , Willd., var. acutifolium multifidum^og^my 
was induced. He believed that if the prothallia of this variety had been 
maintained under the cultural conditions for a longer period of time, 
apogamy might have resulted. In all species excepting \ Pcly podium 
vulgar e, archegonial projections were produced. From processes that 
appeared on the prothallia of Scolopendium vulgar e, S w. , var. ramidossisimum, 
Woll., and Nephr odium dilatatum , Desv., sporangia were formed. The 
apogamous formation of sporangia in these cases is analogous to the 
development of antheridia directly on the fern leaf. A case of apospory 
of this nature was later described by Woronin (1907) in Trichomanes 
Kraussii. The cultural conditions which Lang maintained were evidently 
not uniform, since in every culture some embryos were produced as a re- 
sult of fertilization. No control cultures were used by Lang, and, although 
he exercised great care in his cultural work, no positive conclusion can 
be drawn from his results regarding the actual conditions which induced 
apogamy. 
In a preliminary note, Farmer. Moore, and Digby (1903) reported 
nuclear migrations and fusions in the vegetative cells of the prothallium 
of Lastraea pseudo-mas. A diploid nucleus was thus established in some 
of the cells by a fusion in pairs of the nuclei of adjacent cells. The 
apogamous embryo, according to their description, begins its develop- 
ment from cells whose nuclei have the double number of chromosomes, 
the latter being acquired as a result of the ‘ irregular ’ fertilization or 
4 substitution ’ fusions. Such fusions, as described by these investigators, 
are the first to be reported in ferns. 
Miss Digby (1905) found no reduction in chromosome number in 
the life-history of the apogamous Nephr odium pseudo-mas, Rich., var. 
ads tat a , fifty chromosomes being counted in the cells of both genera- 
tions. Nuclear migrations were found in 73 per cent, of the prothallia 
of the apogamous Nephr odium pseudo-mas, Rich., var. polydactyla , Wills. 
Farmer and Digby (1907) later published a more extensive account of 
their cytological investigations of apospory and apogamy in ferns. Of the 
seven forms studied by them, the following were parthenogenetic and 
aposporous : Athyrium Filix-foemiha var. clarissima , Bolton, A. Filix- 
foemina var. unco-glomeratum , Stansfield, and Scolopendrium vulgar e, var. 
crispum Drummondae. The prothallia of Athyrium Filix-foemina var. 
clarissima , Jones, and Lastraea pseudo-mas var. crista ta apospora were 
produced aposporously. In the former archegonia were produced, but the 
embryo, as also in the latter species, always originated as a vegetative out- 
growth of the gametophyte. In Lastraea [Nephr odium) pseudo -mas var. 
polydactyla, Wills, and L. pseudo-mas var. polydactyla , Dadds, the prothallia 
were produced from spores. Archegonia were never formed, and the embryo 
