397 
of being too hypothetical, and of not distinctly deciding the position of 
Hepaticae. 
Struck, perhaps, with this objection, Adolphe Brongniart has more 
recently proposed a triple division of cellular plants, in the following manner : 
— I. Neither vessels nor foliaceous appendages ; no trace of sexual organs ; 
sporules contained in indehiscent capsules, or bursting irregularly, with no 
kind of proper integument. These answer to the Acotyledones of Agardh 
and the Homonemea of Fries. II. No vessels, but foliaceous appendages ; 
sexual organs doubtful ; sporules contained in great numbers in capsules 
that burst regularly, and have a proper integument. Ex. Hepaticae and 
Mosses. III. Vessels present, and foliaceous appendages; sexual organs 
certainly existing in some : sporules contained in polyspermous and dehiscent, 
or monospermous indehiscent capsules. Ex. Ferns and their allies, with 
Chara. — To the definitions of these, several objections might be taken, parti- 
cularly to all that part which relates to the supposed presence of sexual 
organs ; but the divisions themselves appear less exceptionable than any of 
the others. They are moreover in conformity with the view that has been 
taken of the subject by Theodore Nees v. Esenbeck in his and Ebermaier’s 
excellent Medical Botany. 
Without exactly adopting any of the foregoing divisions, I have endea- 
voured to seize the best points of each in framing the following alliances ; 
of which Filicales and Lycopodales may be considered to correspond with the 
first section, Muscales and Charales with the second, and Fungales with the 
third. 
Alliance I. FILICALES, 
Filices, Juss. Gen. 14. (1789); Swartz Synops. Filicum (1806); Willd. Sp. PI. \o\. 5. 
(1810) ; R. Brown Prodr. 145. (1810) ; Agardh Aph. 115. (1822) ; Kaulfuss Enum. 
(1824) ; Spreng. Syst. Veg. vol. 4. (1827) ; Hooker and Greville leones Filicum 
(l827 — 1829) ; Blume, FI. Javee (1828). Schott's Genera Filicum (1835) ; Mohl et 
Martins Plantce Cryptogamiew Brasilienses, p. 40. (1834). 
Essential Character. — Leafy plants, producing a rhizoma, which creeps below or 
upon the surface of the earth, or rises into the air like the trunk of a tree ; this trunk con- 
sists of a hollow cylinder, of equal diameter at both ends, growing at the point only, con- 
taining a loose cellular substance which often disappears ; it is coated by a hard, cellular, 
fibrous rind, which is much thicker next the root than at the apex, and it is itself com- 
posed of the united bases of the leaves. Wood when present, consisting almost exclusively 
of large scalariform or dotted ducts, imbedded in hard plates of thick sided elongated 
cellular tissue. Leaves (or fronds) coiled up in vernation, with annular ducts in the vas- 
cular tissue of their petiole, either simple or divided in various degrees, traversed by dicho- 
tomous veins of equal thickness, which are composed of elongated cellular tissue, with 
occasional ducts; cuticle frequently with stomates. Reproductive organs consisting of 
thecw or semitransparent cases arising from the veins upon the under surface of the leaves 
or from their margin. Thecce either pedicellate, with the stalk passing round them in the 
form of an elastic ring, or sessile and destitute of such a ring ; either springing from beneath 
the cuticle, which they then force up in the form of a membrane (or indusium), or from 
the actual surface of the leaves. Sporules usually triangular, arranged without order 
within these thecae. Sometimes the leaves are contracted about the thecae, so as to assume 
the appearance of forming a part of the reproductive organs, and sometimes the place of 
theca is supplied by the depauperated lobes of the leaves. 
Affinities. These, which are by far the most gigantic of Acrogens 
sometimes having tmnks 40 feet high, approach the nearest to the 
Flowering classes by Cycadaceae, which may be considered to have much 
affinity with them, on account of the imperfect degree in which their vascular 
