1904 | LYON: EVOLUTION OF THE SEX ORGANS 285 
and whose sperms have every appearance of being normal. The 
member of sperms produced, however, may be smaller than usual. 
Sometimes two or three antheridia are developed from the neck 
cells of the same archegonium (jig. 9). This is cogent evi- 
dence that the cervical cells of an archegonium are sterilized 
gametogenous cells which may regain poten- 
tiality. Goebel (9) describes the same phe- 
nomenon of antheridia developing from the 
neck cells of archegonia of Hemionitis palmata 
and Lygodium japonica. He comments thus: 
‘‘Wir kénnen dieses Verhalten als eine Altens- 
erscheinung betrachten.”’ But that can hardly 
be the explanation of aay phenomenon in this 
a apleleaama” case, for the prothalli were young and dis- 
tion of an archego- played unusual vigor. All stages of arche- 
onthe Lycopodium gonia and antheridia appear ina single thallus. 
ts pes abe’ Aberrant antheridia have been less fre- 
quently noticed. The form of the male organ 
seems to be singularly simple and monoto- 
ee nous throughout the bryophytes. I have 
ariation of frequent occur- 
~via however, in the antheridium of 
Atrichum angustatum. The spermatog- 
€nous cells are separated into two 
8roups by a transverse septum consist- 
~ of a single layer of cells formed 
m fertile cells that ceased to divide 
early in the development of the 
organs, and at about the period at which 
the wall is differentiated. Sometimes 
these two groups matured pari passu; 
again, the sperms were ready to escape. 
fro . — Longitudinal me- 
4 m the upper or under chamber in- ,. zs = Oe 
different] : dian section of an archegonium 
ba y, while the other group Was of Adiantum cuneatum, showing 
mature (jig. 13). This division of double egg apparatus: ¢, €g85; 
the ; ; ; 
Sperm mass is the rule in Selagi- v, ventral canal cells. 
Vi * . ° z= 7 i i 
. apus either with or without the intervening diaphragm as 1n 
richum and in certain Hydropterideae. As is well known, at 
