1 1 1 
Danaea simplicifolia , Rudge . 
to confirm in the prothalli examined by him 1 ; neither 
observer, however, found them on the actual margin. Even 
after the cotyledon of the young plant has completed its 
development, antheridia may still be found in process of 
formation on the prothallus (cf. Fig. 3 at an.). 
Perhaps the most notable point about the prothallus of 
D. simplicifolia is that the rhizoids are septate, three or four 
transverse walls being readily observable (cf. Fig. 6). Prof. 
Campbell 2 mentions, with regard to the other genera of 
the Marattiaceae, that the c root-hairs ’ of the prothallus are 
unicellular 3 . These rhizoids of Danaea remind one not 
a little of the protonema of a Moss. 
Antheridium. 
The antheridia agree in every respect with those of A ngio- 
pteris and Marattia , at least with those which may be con- 
sidered as of the normal type (cf. Fig. 12 with the corre- 
sponding figures of Jonkman and Campbell’s papers). The 
figures for one genus would do almost as well for either of 
the other two. A modification in the usual mode of develop- 
ment, which has not been described for either Angiopteris or 
Marattia , was, however, noticed in D. simplicifolia , although 
there is no reason why it should not occur in these genera also. 
The usual process, to quote Prof. Campbell 4 , is as follows : — 
‘ The antheridium arises from a single superficial cell, which 
first divides into an inner cell, the mother-cell of the sperm- 
cells, and an outer cover-cell. The latter divides by several 
curved vertical walls which intersect, and the last wall cuts 
off a small triangular cell, which is thrown off when the antheri- 
dium opens and allows the sperm-cells to escape. Before 
these are completed, however, cells are cut off from the 
adjacent cells of the prothallium, completely enclosing the 
mass of sperm cells.’ The peculiarity observed in Danaea 
1 Loc. cit., p. 2 it. 2 Loc. cit. (b), p. 257. 
3 I was able to confirm this statement with regard to Angiopteris , Prof. J. B. 
Farmer having very kindly placed prothalli bearing young plants at my disposal. 
4 Loc. cit. (a), p. 5. 
