52 Remarks on the Natural order Cycadeee. 



In the Ferns and other flovverless plants, we find the reproductive 

 organs either obscure or imperfect; and in the next succeeding step, 

 (the Coniferse and Cycadese,) those organs, though distinctly char- 

 acterized, are still formed in the most simple manner and accompa- 

 nied with a corresponding simplicity in the structure of the wood, 

 the leaves, and the whole vegetable system. As also we perceive 

 the remains of the carnivorous and lacustrine mammalia succeeding 

 in a later formation to those of the more primitive animals, so we find 

 the Palms, some of the Liliaceae, and many dicotyledonous plants, 

 gradually assuming their respective places, just as the improving 

 condition of the globe became more fitted to their respective organ- 

 izations. In this way the history of the earth is unfolded to us; and 

 such are the proofs perpetuated and unchanged through centuries of 

 time, which show that it is through successive ages, and by -a slow 

 and gradual series of changes that the globe has acquired its present 

 more perfect state ; and that both departments of organized matter 

 have advanced with equal steps and mutually dependent relations to 

 that condition (perhaps still progressive,) in which they are found 

 at the present moment, 



EXPLANATION OF THE PLATES. 



PI. I, Cycas revoluta, with the crown of contracted leaves in the centre bearing- 

 the nearly mature seeds. 



PI. II, Fig. 1, the contracted leaf or imperfect ovarium, with the full grown 

 ovules upon the margin of its lower half. Fig. 2, the 3^oung ovulum or female 

 flower: a, e.ros^ome, or opening in the outer membrane, (primine.) b, the dilated 

 apex of the secundine or inner membrane, through which the foramen leads to the 

 nucleus. Fig. 3, the full grown seed : e, outer integument of a soft texture : d, in- 

 ner integument, hard and bony, a, tercine, or third coat enveloping the nucleus 

 (/) : b, minute columnar process connecting the nucleus with the foramen c. 



Fig. 4, impregnated nucleus, a, embryo. S, albumen. All of the size of nature. 



Note, — It is proper to observe, that in the specimen of C. revohUa here figured, 

 the ovula (there being no male flowers in bloom at the same time,) have not been 

 impregnated. This perhaps renders it still more interesting ; for while the ovula 

 have gone on gradually acquiring color and consistency, as is the case when impreg- 

 nated, there has of course been no embryo produced in the nucleus, which has the 

 usual homogeneous appearance, with a trifling cavity in many of the matured spe-, 

 cimens, where the embryo should have been found. It presents therefore a strong 

 point of interest, in the fact that the coats of the seeds being here quite perfect 

 and distinguishable, are of course proved, contrary to the opinion of some car- 

 pologists, not to be the product of fecundation. In PI, II, Fig. 4, the einbrj-o a is 

 shown as figured by Richard and others. 



The drawings in both plates were executed from a noble specimen in the exotic 

 collection of J. W. Knevels, Esq., Newburgh, N. Y., which also contains several 

 other fine specimens of Cycadeae. This plant, probably about thirty years old, 

 has flowered this season for the second time. The trunk is about four feet iri 

 height, the crown of foliage about eight feet in diameter, and the tiift of pontra,ct= 

 ed leaves iu the center eighteen inches in diameter. 



