313 
vegetation of the stem of Cycadacese, or from a too superficial consideration of 
such points as were really well known. The affinity of Cycadacece and Palms 
does at first sight appear probable, in consequence of the large pinnated leaves 
and simple cylindrical stems of both tribes ; but here I think the resemblance stops, 
Cycadacese have a gyrate. Palms a convolute vernation ; Cycadacese are naked- 
seeded and bear their seeds on the margins of a contracted leaf. Palms have the or- 
dinary inflorescence of flowering plants : Cycadacese are dicotyledonous. Palms 
monocotyledonous ; and finally, the internal structure of the trunk of Cycadacese 
is essentially exogenous, as is now perfectly well known : the affinity of Cyca- 
daceae is therefore not with Palms. With regard to the nature of the evi- 
dence by which their strict relation to the Pine tribe is to be established, it 
may be observed, that they both are dicotyledonous in seed, both have naked 
ovules constructed in a similar remarkable manner, and borne in both cases 
not upon a rachis, but upon the margin or face of metamorphosed leaves ; that 
they have the same peculiar form of inflorescence, the same kind of male 
flowers, the same constant separation of sexes ; that there is a like imperfect 
formation of spiral vessels, a most important consideration ; and finally, that 
they both agree in having the vessels of their wood marked with circular disks ; 
a character which, if not confined to these two tribes, is extremely uncommon 
elsewhere. The difference between the cylindrical simple stem of Cycadaceae 
and the branched conical one of Coniferse arises from the terminal bud only of 
the former developing, its axillary ones all being uniformly latent, unless 
called into life by some accidental circumstance, as in the case recorded in the 
Horticultural Transactions, 6. 501. ; while in Coniferse a constant tendency 
to a rapid evolution of leaf-buds takes place in every axil. With regard to 
their foliage, on which the diflference of their aspect chiefly depends, the leaves 
of Coniferae are minute and undivided, while those of Cycadacese are very 
large and pinnated ; in both they are simple, and in Coniferse there is a ten- 
dency to a higher development in the scales of the cones, while in Cycadacese 
there is a corresponding contraction firstly in Cycas itself, and especially in 
Zamia, in which the contraction takes place, to exactly the same point as the 
evolution of Coniferse. 
Geography. Natives of the tropics of America and Asia ; not found in 
equinoctial Africa, although they exist at the Cape of Good Hope and in Ma- 
dagascar. Brown Congo, 464. 
Properties. The only remarkable quality in the order is the production 
of a kind of Sago, by the soft centre of Cycas circinalis. They all abound in 
a mucilaginous nauseous juice. 
GENERA. 
Zamia, L. Encephalartos, Lehm, 
Arthro zamia, Rchb. Cycas, L. 
Order CCXXX. CONIFER^,] 
or I The Fir Tribe. 
PINACEiE. J 
CoNiFERiE, Juss. Gen. 411. (1789); Mirbel Eltmens, 2. 906. (1815) Brown in King’s 
Voyage, Appendix, (1825) ; Rich. Monogr. (1»26) ; DC. and Duly, 431. (1828j ; 
Lindl. Synops. 240. (1829). — Abietin.e et Cupressin^., Rich. 1. c. (1826) ; Bartl. 
Ord. Nat. 94 et 95. (1830). — Abietin.®, Prodr. Norf. 35. (1833). — Conace®, 
Lindl. Key. No. 232. (1835). 
Essential Character. — Flowers monoecious or dioecious. Males monandrous or 
