ai'e aciiuainted with the internal structure of a seed I'efei'red to a definite genus
and species of the Cycadofilices. The seed has a complex organisation. Tlie
nncellns is adherent tho the testa until near the microiiylai- end, where it becomes
free. The njijier part ot the nncellns possesses a pollen-chamber, more elaborate
than that of recent Cycadean seeds, as it is traversed by a central column, reducing
the actual cavity of the chamber to a narrow, bellshaped crevice, in which the pollen-
grains are found. The neck of the pollen-chamher protruded slightly from the micropyle,
and no doubt directly received the iiollen-grains, whether brought by the wind, oi',
as the abundance of glands has suggested, by insect-agency (Fig. 15).
A concentric vascular
strand enters the
chalaza and there breaks
np into about 9 collateral
bundles, traversing
the inner zone of the
. b- testa, which at the iipjier
end expands into the
complex canopy, a lobed
and chambered structure,
each loculiis, filled
in life by a delicate
tissue, receiving one of
the vascular bundles.
The lobed cujmle,
forming a loose investment
round the seed,
itself j)ossessed an elaborate
vascular siqiply,
derived from the bundle
of the pedicel, from
Kig. 9. L y g i n o d e n d r o n ol d l iaminm. Transverse section of
rachis of frond. / A"-shaped xylem of bundle, 7>. b. ph phloem, com-
])letely surrounding the xylem; hv hyjiodermn. x about 35. From
Scott, 1900, after a ])hotograph. WujjaiMSON Colin 145.
which it branched off a little below the chalaza.
Thus the organisation of the seed of Lygi nodendr on, while showing a
general Cycad-like character, has marked peculiarities of its own. The nearest analogy
among other fossil genera is perhaps to be found in Gnetops i s , described by
M. R e n a u l t , in which however tlie cnpnle encloses several seeds. R e n a u l t (1885).
At least four other species, referred to the genus Lag eno s toma as at present
constituted, are known, two with structure preserved, while the two others have only
been found as casts. All these must clearly have belonged to plants closely allied
to Ly g in o d e n d ro n Oldhami nm. One of these sjiecies, La g e n o s toma Sinclai r i
K id s t o n , is of great interest for two reasons; as in L. Lomaxi, the seed is clearly
invested by a cupnle, and secondly the seeds are found in connection with the branches
of a naked rachis, distinctly suggesting the fertile frond of a Sphenopt e r i s (A r b e r , 1905).
(Figs. 16 and 17) It is now extremely probable that the „indusia“ of S t u r ’s Calym-
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