224 CYCADEACE.E. [Gymnogens. 



angular, collected in masses. ? consisting of naked ovules, placed beneath peltate 

 scales, or at the base of flat ones, or on the margins of contracted leaves. Seeds hard or 

 spongy-coated nuts, with one or more embryos suspended by a long funiculus in a 

 central cavity of large white fleshy or mealy albumen ; the cotyledons unequal, more 

 or less connate ; radicle superior. 



One of the botanists who originally noticed the plants that constitute this Order 

 referred them to Feras ; an opinion to which Linnaeus, having first adopted the idea of 

 Adanson that they were related to Palms, finally acceded. He was followed by others, 

 until, after some suggestions by Ventenat that the genera Cycas and Zamia ought to 

 form a particular tribe, the present Order was finally characterised by the late L. C. 

 Richard in Persoon's Synopsis, in 1807, %\ath the observation that it was intermediate 

 between Ferns and Palms. The opinion of the affinity to Ferns seems to have been 

 thus generally adopted in consequence of the striking resemblance on the part of most 

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

 suggested rather by a vague notion of some general similarity, as, for instance, in their 

 cyluidrical trimks, than by any precise kjiowledge of the structure of Cycads. It 

 is only A\dthin a few years that more accurate inquiries have determined the real nature 

 of theh' affinities. In 1825, the publication of Brown's remarks upon the ovule, in 

 which he demonstrated the similarity of conformation between the flowers of Cycads 

 and Conifers, suggested new ideas of the affinities of both Orders ; and the deter- 

 mination, in 1829, by Adolphe Brongniart, of the resemblance between them in the 

 structm'e of the vessels of theii' wood, while it decided the near relation of Conifers and 

 Cycads, confirmed the proximity of the latter to Ferns, and showed the inaccuracy 

 of the ideas formerly held of a close resemblance between the latter and Palms. With 

 regard to the natiu-e of the evidence by which their strict relation to Conifers is esta- 

 blished, it may be observed, that they both ai'e dicotyledonous in seed, both have naked 

 o%Tiles constructed in a similar remarkable manner, and borne in both cases not upon 

 an ordinary axis of gi'owth, 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 ; and that they both agree in ha\Tng the vessels of their wood marked with 

 circular disks ; a character which, if not confined to them, is imcommon elsewhere. 

 The difference between the cylindrical simple stem of Cycads and the branched 

 conical one of Conifers ai'ises from the terminal bud only of the former developing, its 

 axiUary ones all being uniformly latent, unless called into Hfe by some accidental cir- 

 cumstance, as in the case recorded in the Horticultural Transaction, 6. 501 ; while in 

 Conifers a constant tendency to a rapid evolution of leaf-buds takes place in every axil. 

 With regard to their foliage, on which the difference of aspect chiefly depends, the 

 leaves of Firs are minute and undi%dded, while those of Cycads are very large and 

 pinnated ; in Conifers there is a tendency to a higher development in the scales of the 

 cones, while in Cycads there is a corresponding contraction, firstly in Cycas itself, 

 and especially in Zamia, in which it takes place to exactly the same point as the evolu- 

 tion of Conifers. To this it may be added that the cones of Araucaria, among Firs, and 

 of Dion among Cycads, are almost undistinguishable. 



Natives of the tropics and temperate parts of America and Asia ; but not foimd in 

 equinoctial Africa, although they exist at the Cape of Good Hope and in Madagascar. 

 — Brown Congo, 464. Dion edule occurs in Mexico, where it seems to be common in 

 some places. According to Mr. Bunbmy, Zamias are among the forms of vegetation 

 that characterise the eastern part of the" colony of the Cape of Good Hope, especially 

 the great tract of thicket extending along the Caff'er frontier.— ZowcZ. Journ. Bot. 2. 40. 

 Upon the west coast of New Holland a Zamia, supposed to be Macrozamia spirahs, 

 grows to the height of 30 feet. The undoubted remains of Cycads attest their ha>Tng 

 once formed a considerable portion of the vegetation of Great Britain ! 



All the species abound in a mucilagmous nauseous juice. With this, however, is 

 mixed, in many instances, a very considerable quantity of starch, whence they are 

 common articles of food in the cormtries where they grow. At the Cape of Good Hope 

 various species of Encephalartos are called Caff'erbread. The great seeds of Dion edule 

 furnish a kind of ArroA\TOot in Mexico. A similar material of excellent quality is 

 extracted m the Bahamas and other West India islands from Zamia pumila and other 

 dwarf species. In Japan a kmd of sago is procured from the cellular substance 

 occupring the interior of the stem of Cycas revoluta. This is said by Thunberg to be 

 held in the highest esteem ; soldiers are able to exist for a long time upon a very small 

 quantity of it, and it is contrary to the laws of Japan to take the trees out of the coimtry. 

 The nuts are also eatable. So also is a sort of sago extracted from Cycas cu-cinalis, 

 whose fruit is eaten in the Moluccas, and a kind of flour of bad quahty is proeiu-ed from 



