GTMNOSPEEMIA. 365 



taining one embryo or several, in fleshy or inealy perisperm. 

 Illustrative Genera : Cycas, L. ; Dion, Lindl. ; Zamia, L. ; Ence- 

 jpkalartos, Lehm. ; Macrozamia, Miq. ; Stangeria, Moore. 



Aflanities, &c. With the habit and appearance of Palms, and in some 

 cases of Ferns (especially in the genus Stangeriti), these plants agree with 

 Pinacece in the essential peculiarities of the organization of their flowers 

 and seeds, while the distribution of the reproductive organs over the leaf- 

 like carpels and the antheriferous scales in Cycas, together with the occa- 

 sionally circinate vernation of the leaf-segments, connect this Order with 

 the Ferns, thus strengthening the relation between the Gymnosperms 

 and the higher Cryptogams, which is so evident in the affinities between 

 Pinaceee and Lycopodiaceas. The relationship to the higher Cryptogams 

 is further indicated by the multicellular pollen of Cycads, which is analo- 

 gous to the microsporangia of Rhizocarps. 



Some difference exists in the condition of the reproductive organs. The 

 flower-cones, composed of imbricated scales, appear to be axillary produc- 

 tions in Zamia ; but in Cycas they are formed from the terminal bud, which 

 subsequently grows on (as in the Pine-apple), so that here the terminal 

 inflorescence does not arrest the growth of the axis : the formation of cones 

 occurs at intervals ; and when the scales fall off, after the pollen or the 

 seeds are mature, the stem is found marked alternately with bands of scars 

 of two kinds, those of the true leaves and those of the floral leaves (carpels 

 and stamens). In Zamia the cones are lateral, like the spadicee of many 

 Palms. In Cycas the female coaes are formed of large flat leafy carpels, 

 with ovules arranged at some distance apart on the margins ; the male cones 

 are likewise formed of leafy scales, bearing numerous anthers (or loculi) 

 scattered over the lower surface, the loculi being commonly grouped in 

 fours like the sporanges of Mertmsia. In Zamia the cones more nearly 

 resemble those of Pinaceae : the male cones are formed of peltate scales 

 (with an apophysis as in the ripe cones of Cupressus), with the pollen- 

 cases under the overhanging head ; the female cones are composed of some- 

 what peltate scales bearing only a pair of ovules at the base. The pollen- 

 sacs are numerous, sessile, or stalked, on the under surface of the thick per- 

 sistent staminal scales. The pollen-cells are at first simple and more or less 

 spherical, but subsequently tney divide into two or more cells of different 

 sizes, the pollen-tube ultimately protruding from the larger cell. The 

 compound pollen, forming a sort of male prothalliuna, is similar to that of 

 Pinaceae. 



L. C. Richard regarded the female flower of Cycads as formed of a 

 gamosepalous calyx adherent to a half-inferior ovary. Payer thought the 

 ovary was achlamydeous, surmounted by a short style. Alexander Braun 

 also considered the tegument of the ovule to be ovarian. Van Tieghem, 

 basing his opinion on the arrangement of the vascular bundles, thinks the 

 Cycads are truly Gymnospermous, the ovules being borne on the edges 

 of a flat leaf. Gris also arrived at the conclusion that the outer covering 

 of the ovule was of the nature of an ovular coat, its filiform prolongation 

 being the micropyle, not a style. In the ovule of Cycas, as of Ricinus, the 

 attached portion of the nucleus, where the coat is still confluent with it, 

 is covered with a network of vessels proceeding from the single bundle 

 which passes, under the name of raphe, through the coat of the ovule. 



