J^atural Order Cycadacece. 309 



cordiii<r to Richard, of a monosepalous perianth or calyx, envelopinsr or 

 adheriiiir to an unilocular ovarium, which contains the true seed. He 

 considers the ajjerture at the apex of the outer coat to be the style, and 

 the projecting point of the second, the stigma. Brown, on the contra- 

 ry, suggested that the calyx. Sec. of Richard are but the membranes of 

 the ovula, and in the mature state the integuments of the seed; in short, 

 that the bodies called by Richard and other writers the female flowers, 

 are naked ovula, borne upon the margins of a contracted leaf, which 

 last may be considered as an imperfect and open ovarium. The im- 

 pregnation he suj)])osed to take ))lace ihrouuh the foramen of the ovu- 

 lum, (the perforated stigma of Richard,) their being (contrary to the 

 usual stru(;ture in phenogamous plants,) no style or stigma through 

 which the pollen can find its way to that body. These ideas, so start- 

 ling and paradoxical at first sight, were slowly received even by the 

 most acute botanists, but have finally been almost universally adopted. 

 The so-called naked seeds of Linnaeus, having been demonstrated to be 

 one-seeded fruits, it appears that the Cycadacefe and Coniferse alone 

 have the peculiarity of producing truly naked seeds, and that they com- 

 pose therefore a distinct natural group, to which the uame of Gymnos- 

 permse has very appropriately been given. 



" Aside from an examination of the ovula themselves, and their in- 

 teguments, the botanist who studies the structure of the organs of re- 

 production in Cycadacese, cannot but be convinced, that what were 

 formerly called pistillate flowers are simply ovula in the first place, and 

 afterwards naked seeds. The modified leaf, bearing the ovula upon its 

 face or margin, is undoubtedly a carpellum in an imperfect state of de- 

 velopment, the seeds of which would be enclosed in an ovarium, if 

 the edges of that carpellary leaf wore folded together in the usual man- 

 ner. In Cyctis cii-cmalis, the ordinary appearance of the piimated leaf 

 is so far departed from as to exhibit, in fact, a flat, scale-like carpel, 

 with the rows of ovula ui)on either margin, thus closely resembling an 

 ovarium formed of a single carpellum, (such as a follicle or legume,) 

 spread open. In C. reiwhda the leaf is in a less altered state, having 

 at the extremity contracted ])innated divisions; but the part occupied by 

 the ovula is, as in C. circinalis, the margin of the leaf. If, therefore, 

 the pistillum be a modified leaf or cari)elluni, from the edges of which 

 are produced the ovula, as is now admitted by the first stiuctural bota- 

 nists, the envelopes of the bodies which constitute the female organs in 

 Cycadacea^ and Coniferje cannot be the calyx and ovarium, or indeed 

 any thing else than the proper integuments of the seed; inasmuch as 

 these bodies are produced upon the margins of the ovarium, the sum- 

 mit of which, if it were folded together, would become the style or 

 stigma, and at the base, or surrounding which, would be found, perhaps, 

 if in a state of sufficient development, the true floral envelopes. This 

 argument receives additional force from the well known tendency of 

 many leaves to produce upon their margins, either buds, (as in Bryo- 

 phyllum and other plants,) which are in fact distinct individuals, or 

 ovula, which are capable of becoming such by impregnation." 



The observations of European botanists have been generally 

 made with the C. circinalis, the seed of which appears to be in 

 a less perfect state of development than the C. revoluta. 



The closing remarks of Mr. Downing will be read with inter- 

 est; iiis conclusions respecting the order before us, are, that " it 

 is evident that the so called female flowers and fruits in Cycada- 

 ceff> and Coniferaceae are naked ovula and seeds, not only from 

 their position, u])on an imperfectly formed ovarium, (the convo- 



