FERNS. 175 



a layer of hard woody tubes. There are no leaves ; but the external articulated 

 organs much resemble them. The fruit is borne on the top of the stem, and consists 

 of a number of masses sessile upon the common rachis. They are widely distributed^ 

 and have the peculiarity of containing a large quantity of silex or flint in their cuticle ; 

 so much so, that the Equisetum hyemale and other genera are used in the polishing of 

 metals and furniture. 



The Urn Mosses are small, terrestrial, or aquatic plants, with an axis of growth 

 and minute imbrocated leaves, and differ from all other Mosses in the structure of 

 their two kinds of reproductive organs. They are an interesting and extensive division 

 of the family of Mosses, and are more commonly found in temperate than in tropical 

 climes. Wherever there is moisture, even if soil be almost absent, they will grow, 

 and they are the first to cover a barren coast, as they are the last to linger when the 

 atmosphere ceases to be capable of affording nourishment to vegetation. The Sphagnum, 

 Polytrichium, and almost all plants vulgarly known as Mosses, belong to this division. 



FERNS. 



The highest division of the Cryptogams is that known as Ferns (Filices), a division 

 which, in the degree of its organization, far exceeds that of any yet mentioned. 

 They consist of " leafy plants producing a rhizome, which creeps below or upon the 

 surface of the earth, or rises into the air like the trunk of a tree." "When a stem 

 exists it is usually simple, and of even diameter throughout, and bears a tuft of leaves 

 on its apex, after the fashion of Palms and other endogenous plants, and is composed of 

 cellular, woody, and scalariform tissues. The reproductive organs are spore cases, 

 arising from the veins on the under surface, or other part of the leaves ; or they are 

 situate beneath the cuticle, which they thus throw up in the form of an indusium. 



This class is divided into three portions the Ophioglossus or Adder's-tongues, the 

 Polypodiaceae or true Ferns, and the Danaeaceas or Danaeaunts ; and of these the middle 

 one, or that of true Ferns, contains nearly the whole of the members of the class. "We 

 regret that our space does not permit us to enter into detail into this beautiful, varied, 

 and very interesting tribe of plants ; and the more so, that at the present moment the 

 Ferns and the Orchis have attained to an enviable popularity. 



The Adders-tongues are minute plants, closely allied to the Club Mosses (Lycopo- 

 diacece), with a hollow pithless stem, containing woody fibre, and possessing leaves with 

 netted veins 



Its reproductive organs consist of spores contained within spore-cases, which are 

 arranged on a spike on the sides of a contracted leaf. The Dangeacese, on the other 

 hand, are true dorsiferous Ferns, with reproductive organs sunk within or seated upon 

 the back of the leaflets. There is also, as in the Adder's-tongue, an absence of the 

 elastic ring, which is indicative of true Ferns. Both of these divisions of Ferns are 

 very small, containing together only nine genera. 



The true Ferns or Polypodiacese (vaguely designated Filices) are distinguished by 

 the presence, on the spore-case, of a ring or band of coarse meshes distinctly different 

 from the tissue of their sides, and too strong to be broken through, when the case opens 

 to discharge its spores. A few genera are considered edible, as, for example, the Pteris 

 esculenta, Cyathsea medullaris, Diplazium esculentum, and Gleichenia Hermanni. The 

 Java Fern is also nutritive, whilst the Aspidium fragrans has been employed as a 

 substitute for tea, and the Pteris Aquilina and Aspidium Filix-mas have been used in 

 the manufacture of beer. The genera are very variously distributed over the face of the 



