NATURAL ARRANGEMENT. 



543 



SECOND GRAND DIVISION, CELLULA'RES. 



Genei-a 376, Species 2859 ; Hot-house Species 202 ; G>-een.house Species 84; Hardy Ligneous Species 0; 



Hardy Herbaceous Species 2573. J feet ; 21 feet ; * 2 feet. 



The characteristics of this division have already been explained in the preliminary observations upon the 

 natural orders ; and the remarks which were required for each natural order of Cellulares have already been 

 given in Cryptogamia in the body of the work. It has, therefore, been thought advisable to adopt from Pro- 

 fessor Agardh such observations as he has made upon the orders, as a sort of contrast to those already given. 



CLASS I. FOLIA^CE^E. 



Genera 103, Species 837 ; Hot-house Species 202 ; Green-house Species 84 j Hardy Ligneous Species ; 

 Hardy Herbaceous Species 127. 1 feet ; 21 feet ; * 2 feet. 



502. ORDER I. FILICES. 



Genera 53, Species 380 ; Hot-house Species 201 ; Green-house Species 82; Hardy Ligneous Species ; 

 Hardy Herbaceous Species 97. 1 feet ; 19| feet ; ^ feet. 



Of these the stem is perennial, often subterraneous and creeping, and occasionally becoming arborescent 

 and leafy above the ground. The fronds or leaves are usually pinnatifid, and more or less compound ; some, 

 times nearly simple and entire, with reticulated veins. The capsules are minute, one-celled, seldom many- 

 celled, brown, membranous, and surrounded by a thick articulated elastic ring, irregularly bursting, and either 

 clustered on the lower surface of the frond, or compound in spikes. Their vernation is circinate, and some 

 are propagated by bulbs. The old botanists denied any fruit whatever to Ferns ; believing the seeds of these 

 plants to be so rare as to invest any body with invisibility who could collect them. Afterwards, their capsules 

 were believed to be their seeds. Linnatus, and some others, doubted whether their fructification were seeds or 

 pollen. Finally, the experiments of Ehrhart and Lindsay proved, beyond all cavil, that they were really seeds. 

 As to the male organs nothing is known ; some suppose them to be glands of the frond, others the elastic ring, 

 some the indusium, and others the pores of the epidermis ; lastly, Martius has supposed them to be the mem- 

 brane including the spiral vessels. Ferns are chiefly inhabitants of the torrid zone, becoming rarer as we 

 approach the poles. They delight in a humid soil, and they often grow parasitically upon trees. The medi- 

 cinal virtues of some are highly astringent, of others anthelmintic, of otners purgative ; some have acquired 

 celebrity for their pectoral, otners for their corroborant, qualities. The young leaves and roots of some 



