Developments of the Oophyte in Tricho manes. 285 
large numbers (Fig. 30). Even before the first gemma is 
mature, a fresh sterigma may begin to be formed at the foot 
of the first (Fig. 41) as a papillar outgrowth. The succession 
of sterigmata thus formed is not unlike that of the anthcridial 
cells on the branched hairs of Fucus. 
It will now be evident that in all essential points the forma- 
tion of gemmae above described as occurring in the aposporous 
prothalli of Trichomanes citatum corresponds to that described 
for the prothalli of the presumable Trichomanes by Cramer; 
further that there is in it nothing at variance with the less 
complete accounts of similar formations given by Mettenius 
and by Goebel for other species. The conclusion to be drawn 
is, that the formation of gemmae is a wide-spread phenomenon 
in this genus. 
Sexual Organs. — It may be objected, on the ground of the 
description above given, that it is mere assumption to say that 
the protonemal filaments and flattened outgrowths observed 
are really of an oophytic nature, and belong to the sexual 
generation ; and it is true that no sexual organs have as yet been 
observed on the prothalioid growths derived from the Edin- 
burgh plant ; but the longer established plants at Kew pro- 
vided numerous antheridia , which, though never observed in the 
perfectly mature state, are still very similar to those described 
for other species of Trichomanes. They are produced, with very 
few exceptions, on the protonemal filaments, occasionally also 
on the margins of the flattened expansions. Archegonia have 
never been seen on any of the cultures of this species, and the 
observations of apogamous budding, to be detailed below, lead 
me to regard it as possible that no archegonia are formed at 
all in this plant. However this may be, the general character 
of the protonemal and flattened outgrowths, the absence of 
vascular tissue and of the branched conical hairs so character- 
istic of the sporophyte, the presence of gemmae similar to those 
observed by others on the sexual thallus, and lastly the 
presence of antheridia, suffice to show, without any room for 
doubt, that the protonemal and flattened outgrowths truly 
represent the oophyte, even though they may be produced 
