48 Itemarks on the Natural order Cycadece. 



scale-like carpel, with the rows of ovula upon either margin, thus 

 closely resembling an ovarium formed of a single carpellum, (such 

 as a follicle or legume,) spread open. In C. revoluta the leaf is in 

 a less altered state, having at the extremity contracted pinnated di- 

 visions, (PI. II, fig. ],) but the part occupied by the ovula is, as in 

 C. circinalis, the margin of the leaf. If, therefore, the pistillum be 

 a modiiied leaf or carpellum, from the edges of which are produced 

 the ovula, as is now admitted by the first structural botanists, the en- 

 velopes of the bodies which constitute the female organs in Cycadeae 

 and Coniferse 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 summit 

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

 ma, 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 ten- 

 dency of many leaves to produce upon their margins, either buds, (as 

 in Bryophyllum and other plants,) which are in fact distinct individu- 

 als, or ovula, which are capable of becoming such by impregnation. 



The species of Cycas more commonly examined by European 

 botanists, appears to have been C. circinalis, which, with regard to 

 the seed itself, seems to be in a less perfect state of development 

 than the species now before us. Richard's admirable figures repre- 

 sent only the former species; and Professor Lindley's essential char- 

 acters of the order, in his "Introduction to the Natural System," are 

 obviously drawn, so far as relates to Cycas, from C. circinalis.* In 

 the specimen of C. revoluta before us, the most important difference 

 arises from the presence of a brown membranous coating of the nu- 

 cleus, perfectly distinct during the latter part of the growth of the 



* In the " essential character" of Cycadece, given by Professor Lindley, in his 

 " Introduction to the Natural S3rstem," the " pistilliferons flowers" are described 

 as "either collected in cones, or surrounding the central bud, in the form of con- 

 tracted leaves, without finncB, bearing the ovula upon their margins." Such is 

 really the case in C. circinalis, where the leaf is contracted into a flat scale. But 

 in C. revoluta, only that portion of the modified leaf upon which the ovula are 

 produced, is without the usual pinnated divisions. The same distinguished bota- 

 nist likeM'ise states the ^^ gyrate vernation" of the leaves to be an essential char- 

 acteristic of the whole order; v.'hile, so far as v/e have observed, such is actually 

 the case onl}' in C. circinalis, which in the beautifully gyrate disposition of its 

 young leaflets, and also in the whole appearance of the growing plant, exhibits 

 in the strongest manner the affinity of this order to the Ferns. The vernation is by 

 no means gyrate in C. revoluta, nor in our American Zamia, or in such of the 

 exotic species of that genus as we have had an opportunity to examine. 



