110 Mr. J. Morris on recent and fossil Cycadece, 



with sulphuretted hydrogen ; whilst I have found that other 

 kinds are effectually destroyed by such treatment. 



Besides the vegetable and animal forms above mentioned, 

 the sulphur waters during their decomposition afford others, 

 especially under the films that collect on the surface of the 

 water. 



XV. — Remarks upon the Recent and Fossil Cycadece, By 

 J. Morris, Esq. 



The Cycadeae, originally placed by Linnaeus and Jussieu 

 among the Ferns, are an interesting family of plants, from their 

 appearing to form an intermediate place between the Palms, 

 Ferns and Coniferae ; resembling the first in their external 

 habit, the second in the gyrate vernation of their leaves (a 

 character not belonging to the whole family), and related to 

 Coniferae in the ovula being uncovered, or not furnished with 

 any seed-vessel. The affinities of these families, although pre- 

 viously mentioned by C. Richard*, were, in this latter re- 

 spect, finally determined by Mr. R. Brown in his researches 

 into the structure of their reproductive organs, inserted in the 

 Appendix of Capt. King's ^ Voyage to Australia.' 



The stems or trunks of Cycadeae are generally simple, al- 

 though some species of Zamia appear capable of dividing into 

 two or three terminal buds. In Cycas the internal structure 

 consists of a central pith surrounded by two or more circles 

 of laminated vascular and cellular tissue alternating ; in En- 

 cephalartos the central cellular tissue is divided from the ex- 

 ternal by only one circle of woody fibre f. ^^ The stems are en- 

 closed in no true bark, but have a thick case composed of the 

 persistent scales which have formed the bases of fallen leaves ; 

 these, together with other abortive scales, constitute a com- 

 pact covering that supplies the place of bark." — [BucklandX-) 



* * Mem. sur les Coniferes et Cycad^es,' 1826, p. 183. " II n'est aucune 

 famille de plantes qui ait plus de rapports et de ressemblance avec les Coni- 

 feres que celle des Cycadees. Ces rapports nous semblent si grands, que nous 

 pensons qu'il est impossible de distinguer ces deux families, ni par des ca- 

 racteres tires de leursfleurs, ni par des caracteres puises dans I'organisation 

 de leurs fruits. . Les sevds signes distinctifs qui existent reellement entr' elles 

 consistent uniquement dans leur port et la structure anatomique de leur 

 tige, qui en efFet est fort differente dans I'un et I'autre groupe." 



M. Richard, however, appears to have been unaware of the internal 

 sti'ucture of Cycas being stratified ; but describes it as similar to that of 

 Palms : " C. circinalis, Arbor . . . ., ligno albicanti, moUiuti in arboribus mo- 

 nocotyledonibus disposito." 



f In a specimen of E. spiralis, for which I am indebted to the Messrs. 

 Lee of Hammersmith, the external circle of cellular tissue is wanting. 



J Some interesting observations on the structure of the tissues of Cycadeae 

 have appeared by D. Don, Esq., Libr. L.S. Mr. Don remarks, that *' the 



