376 



STRUCTURE OF FERNS. 



seen, from a single Germ-cell ; so that the immediate product of 

 each act of fertilization does not consist (as in the higher Plants) 

 of a single Seed, that afterwards developes itself into a composite 

 fahric, whence are put forth a multitude of leaf- buds, every one 

 of which is capable (under favourable circumstances) of evolving 

 itself into a complete Plant ; but divides itself at once into a mass 

 of isolated cells (Spores), of which every one may be considered in 

 the light of a Bud or gemma of the simplest possible kind, and one 

 of the first acts of which is to put forth other buds, whereby the 



rapid extension of the Mosses 

 Fig. 188. is secured, although no sepa- 



rate individual ever attains 

 more than a very limited 

 size. 



278. In the Ferns we have 

 in many respects a near ap- 

 proximation to Flowering 

 plants ; but thi3 approxima- 

 tion does not extend to 

 their Reproductive apparatus, 

 which is formed upon a type 

 essentially the same as that 

 of Mosses, though evolved 

 at a very different period 

 of life. As the Tissues 

 of which their fabrics are 

 composed are essentially the 

 same as those to be de- 

 Oblique section of Footstalk of Fern-leaf, scribed in the next Chapter, 

 showing bundle of Sealariform Ducts. it win not be re qviisite here 



to dwell upon them. The 

 Stem (where it exists) is for the most part made up of Cellular 

 parenchyma, which is separated into a cortical and a medullary 

 portion by the interposition of a circular series of fibro-vascular 

 bundles containing true Woody tissue and Ducts. These bundles 

 form a kind of irregular network, from which prolongations 

 are given off that pass into the Leaf-stalks, and thence into 

 the midrib and its lateral branches; and it is their peculiar 

 arrangement in the leaf-stalks, which gives to the transverse 

 section of these the figured marking commonly known as ' King 

 Charles in the oak.' A thin section, especially if somewhat oblique 

 (Fig. 188), displays extremely well the peculiar characterof the Ducts 

 of the Fern; which are termed 'sealariform,' from the resemblance 

 of the regular markings on their walls to the rungs of a ladder. 



279. What is usually considered the Fructification of the Ferns 

 affords a most beautiful and readily- prepared class of Opaque 

 objects for the lowest powers of the Microscope ; nothing more 

 being necessary than to lay a fragment of the frond that bears 



