444 BOTANICAL GAZETTE [JUNE 
had made the drawings which appear in connection with this note, 
but was detained from writing at that time. A little later, in 
looking over some back numbers of the current botanical litera- 
ture, I ran across Miss BLack’s paper describing imbedded antheridia 
in Dryopteris and Nephrodium.* It is interesting that with no 
knowledge of Miss BLack’s work I had come to practically the 
same conclusion as that outlined in her paper regarding the origin 
and development of these unusual structures. I publish herewith 
exactly the same figures, without change or addition, as were 
prepared before Miss BLack’s paper was read. No prothallium 
containing unusual sexual organs was studied that did not also 
show normal archegonia and antheridia in all stages of develop- 
ment. ’ 
There can be no question as to the presence of an imbedded 
antheridium in these leptosporangiate ferns very similar to that 
found in the eusporangiates. Compare figs. 11 and 12 of this 
paper with Campbell’s figs. 125 D, 128 B, 152 D.? The origin of 
these antheridia is not so obvious. There is no doubt that, as 
described by Miss Biack, they may have practically the same origin 
as archegonia, but they may present transitional stages between 
normal antheridia and archegonia. Fig. 1 shows a normal young 
antheridium in which the first wall formed was not sufficiently 
concave to reach the basal wall, as is ordinarily but not invari- 
ably the case. Had the initial cell failed to protrude before the 
laying down of this cross-wall, such a structure would have been 
formed as that shown in fig. 2. Here the second wall formed, 
the dome-shaped cell, is much more prolonged than is usual. But 
the protrusion of the outer cell may be much less (fig. 3), or there 
may be no arching at all (fig. 4), when we would have what is recog- 
nized as an early stage in the development of a normal arche- 
gonium. Miss Brack finds that arching occurs only in later 
stages of development, but in Pieris there is undoubtedly a greater 
or less arching of the initial cell in many cases, as if it were unde- 
oe BLACK,, CaRoLINE A., The development of the embedded antheridium in 
Dryopteris stipularis (Wild.) Maxon and “ Nephrodium molle.” Bull. Torr. Bot. 
Club 36:557. 1909. 
? CAMPBELL, D. H., Mosses and ferns. New York. 1905. 
