40 A. Henfrey on the Higher Cryptogamous Plants. 
its sustenance from the foregoing. The fruit is usually of 
iester duration than the leaf-bearing plant. In the Filicoids the 
opposite condition obtains. It is true the prothallia send out cap- 
illary rootlets ; those of the Polypodiaceze and Equisetaceze under 
all circumstances, those of the Rhizocarpee# and Selaginelle fre- 
quently. But the prothallium has a much briefer existence than 
the frondescent plant which in most cases must vegetate for seve- 
ral years before it comes to bear fruit. Yet the contrast is not so 
strong as it appears to be at first sight. ‘The seemingly unlimited 
duration of the leaf-bearing moss-plant depends upon constant 
renovation (verjingung ). “Phenomena essentially similar occur 
in proliferous prothallia of the Polypodiacee and Equisetacee. 
The structure of the lowest Mosses (Anthoceros, Pellia) is less 
complex, and the duration of the fruit-bearing shoots is little ]on- 
ger than that of the fruit itself. On the other hand, the ramifi- 
cation of the prothallium of the Equisetacez is exceedingly com- 
plicated ; its duration is even equal to that of a single shoot. 
“It is a circumstance worthy of notice, that in the. second gen- 
eration of Mosses, as of the Filicoids, destined to produce spores, 
more complex thickenings of the cell-walls regularly oceur feoetlt 
of the peristome of Mosses, wall of capsule and elaters of Liver- 
worts, vessels of Filicoids, &c.,) while in the first generation, 
springing from the iti % such structures are found only ae 
and as exceptions 
"lhe manuer in which the second generation arises from the 
first, varies much more in the Filicoids than in the Mosses. ‘The 
Polypodiaceze and Equisetaceee are hermaphrodite; the Rhizo- 
carpee and Selaginella monecious. All the Filicoids agree in 
the fact that the first axis of their embryo possesses but.a very 
limited longitudinal development ; that it is an axis of the second 
rank which breaks throngh the prothallinm and becomes the main 
axis; further, in the end of the axis of the first rank never be- 
coming elongated in the direction opposite to the summit... All 
Filigoids are devoid of a tap-root, and possess only seni 
ts. 
converted into a sporangium, in the latter into an ovule. In the 
Conifers the embryo-sac also very early becomes detached from 
the cellular tissue MR it. The filling-up of the embryo 
sac with the albumen may be compared with the origin of the 
Serene ae in the: Rhizocarpes and Selaginella. The structure 
the ‘corpuscula’ bears the most striking resemblance to that of 
ihe archegonia of Salvinia, still more to that of the Selaginell- — 
) 
