1904] LYON: EVOLUTION OF THE SEX ORGANS 283 
possible exception of certain mosses. I have a prothallus of 
Lycopodium complanatum bearing fifty or more archegonia; of 
these more than half have binucleate canal cells, and there are 
two instances in which the egg cell is included in the doubling 
(fig.5). The remarkable number of cells in the axial row (often 
14-16) marks these as unique amongst 
known archegonia of the imbedded type. 
I do not recall that Bruchmann (6), to 
whose notable work we are indebted for the 
knowledge of the gametophytes of this and 
other European species of Lycopodium, 
mentions the multiplication of the fertile 
cells, although one of his figures certainly 
shows it; but Treub (7) lays stress on the 
fact that the canal cells of Lycopodium 
Phlegmaria show a marked tendency to 
: form two axial rows. I have taken the 
liberty of copying two of his 
figures (figs. 6, 7). Freub says 
that he frequently found arche- 
gonia of this sort, and all of his 
figures show it. He observed an 
Interesting “monstrosity” twice. 
This was an archegonium whose 
upper neck canal cells increased 
to an abnormal number and were 
Spermatogenous in character. He 
neglected to illustrate this duplex 
Fic. 3.—Longitudi- 
nal median section of an 
ventral canal cells, 
\ 
organ, but in this connection he 
recalls the similar phenomenon 
referred to by Hy (2) in mosses, 
and regards it as of importance. 
In all these variations there has 
been a tendency to increase the 
Ce ie 
oo ‘ 
Fic. 4.— Longitudinal median sec- 
tion of archegonium of Se/aginella apus, 
showing embryo derived from egg and 
ventral canal cells. 
Number of fertile cells by a lateral multiplication of the axial 
row 
In quite another category is the archegonium of Adiantum 
