The Philippine journal of science. [Vol. 67, no. 1]

6

The Philippine Journal of Science

1988

forme, T. (Microtrichomanes) digitatum, H. (Mecodium) abrupturn, H. (Mecodium) polyanthos, H. (Meringium) bivalve, H.
tunbridgense, H. (Mecodium) capillaceum, H. (Meringium)
fusciforme,9 H. (Mecodium) undulatum (Hedwig, cited by Mettenius), H. (Mecodium) rarum (Sadebeck), H. (Mecodium)
dilatatum, T. (Microtrichomanes) palmatifidum,10 and T. (Vandenboschia) draytonianum.11 In other cases three cells are
cut off at the "corners" of the spore, leaving a larger central
cell; this occurs in T. (Vandenboschia) schmidianum (Taschner), T. (Crepidopteris) humile, T. (Vandenboschia) pyxidiferum (Mettenius), and T. (Gonocormus) diffusum (Goebel).
The further development is known for still fewer species.
As generalizations, in "Hymenophyllum" one of the three original outgrowths develops, after forming a short protonema, into
a thalloid structure, one cell thick except along a narrow axis,
bearing archegonia in clusters on cushions near the margin,
and antheridia in various places. The species observed belong
to Hymenophyllum and Sphaerocionium. Cardiomanes behaves
in the same manner (Holloway); and so, I believe, does Serpyllopsis. In "Trichomanes" the protonema forms an extensively branched structure, ultimately producing thalloid structures
which bear the archegonia on short special branches in T. alatum
(Bower) and T. sinuosum (Goebel), or, without thallus, bearing
such branches on the branched filament, in T. (Vandenboschia)
pyxidiferum, T. (Gonocormus) diffusum, T. (Selenodesmium)
rigidum, and T. (Macroglena) strictum. Holloway describes the
gametophyte of T. (Selenodesmium) elongatum, which "has but
a brief filamentous stage, and develops into a large strap-shaped
tissue body whose meristem is situated at the base of a sinus at
its forward end, the archegonia being borne on a series of cushionlike thickenings behind the meristerm,"12 whence it appears
that this structure varies within Selenodesmium. There are a
number of observations of other peculiarities. Mettenius reported exceedingly slow growth of the gametophyte of T. pyxidiferum; and there are other observations to the same effect.
It seems to be of indefinitely long life, and in both known forms
to be capable of vegetative multiplication by the dying off of
old parts and independent survival of the branches. Infection
Mettenius, Hymen. (1864) 489-491, pl. 4.
Goebel, Organographie 2 (1930) 1089.
Campbell, Mosses and Ferns (1905) 373.
Holloway, Trans. N. Zeal. Inst. (1923).