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collected in cones, or surrounding the central bud in the form of contracted leaves without 

 pinnEe, bearing the ovula on their margins. Ovula solitary, naked, with no other pericarpium 

 than the scale or contracted leaf upon which they are seated. Embryo in the midst of fleshy 

 or horny albumen ; the radicle next the apex of the seed, from which it hangs by a long funi- 

 culus with which it has an organic connexion.— Trees, with a simple cylindrical trunk, in- 

 creasing by the development of a single terminal bud, and covered by the scaly bases of the 

 leaves ; the wood consisting of concentric circles, the cellular zones between which are exceed- 

 ingly loose. Leaves pinnated, not articulated, having a gyrate vernation. 



Affinities. One of the botanists who originally noticed the plants that 

 constitute this order referred them to the Fern tribe ; an opinion to which Lin- 

 naeus, having first adopted the idea of Adanson that they were related to Palms, 

 finally acceded. He was followed by other botanists, until, after some sugges- 

 tions by Ventenat that the genera Cycas and Zamia ought to form a particular 

 tribe, the present order was finally characterized by the late M. Richard in 

 Persoon's Synopsis, in 1807, with the observation that it was intermediate 

 between Ferns and Palms. The opinion of their affinity to Ferns seems to 

 have been thus generally adopted in consequence of their striking resemblance 

 in the mode of developing their leaves ; but the supposed relation to Palms was 

 suggested rather by a vague notion of some general resemblance, as for in- 

 stance, in their cylindrical trunks, than by an}' precise knowledge of the struc- 

 ture of Cycadeae. It is only within a fe.w years that a more accurate knowledge 

 of their" structure has determined the real nature of their affinities. In 1825, 

 the publication of Mr. Brown's remarks upon the ovulum, in which he demon- 

 strated the similarity of conformation between the flowers of Cycadese and Co- 

 niferse, suggested new ideas of the affinities of both tribes ; and the determina- 

 tion, in 1829, by M. Adolphe Brogniart, of the exact resemblance between these 

 two tribes in the structure of the vessels of their wood, while it decided the near 

 relation of Coniferae and Cycadese, confirmed the proximity of the former to 

 Ferns, and showed the inaccuracy of the ideas formerly held of a close resem- 

 blance between the latter and Palms. As this is still a matter but ill understood 

 in general, it may be useful to make some further remarks upon the subject. 



It has been said that the dissimilarity between Cycadeae and Coniferae is such 

 as to render it impossible to admit of their close approximation in any natural 

 arrangement ; and that the affinity of Cycadeae being with Palms, the former 

 must necessarily be widely apart from Firs. These views of the subject appear 

 to have arisen either from an imperfect knowledge of the real vegetation of the 

 stem of Cycadeae, or from a too superficial consideration of such points as were 

 really well known. The affinity of Cycadese and Palms does at first sight 

 appear probable, in consequence of the large pinnated leaves and simple cylin- 

 drical stems of both tribes ; but here I think the resemblance stops. Cycadeae 

 have a gju-ate, Palms a convolute vernation ; Cycadeae are naked-seeded and 

 bear their seeds on the margins of a contracted leaf, Palms have the ordinary 

 inflorescence of flowering plants ; Cycadeae are dicotyledonous, Palms monoco- 

 tyledonous ; and finally, the internal structure of the trunk of Cycadeae is essen- 

 tially exogenous, as is now perfectly well known : the affinity of C3 r cadeae is 

 therefore not with Palms. With regard to the nature of the evidence by which 

 their strict relation to the Pine tribe is to be established, it may be observed, that 

 they are both dicotyledonous in seed, both have naked ovula 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 or inflorescence, the same kind of staminiferous flowers, the same constant 

 separation of the stamens and pistils ; that the arrangement of the veins of 

 their leaves is peculiar and identical ; 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 apparently perforated with numerous holes ; 

 a character, as far as is yet known, exclusively confined to these two tribes. 



