2 FERNS. 



outward growth of the main stem or trunk, and are 

 therefore called Exogens, and the One-lobed class by the 

 inward growth, expressed in the term Endogens, so the 

 Lobeless have their distinguishing feature in this respect, 

 adding to their growth by additions to the summit, and 

 thus called Acrogens or Summit-growers. 



The first natural order in the Lobeless class is that of 

 the Ferns (Filices.) In this order Ave still find woody 

 fibre, though the great bulk of the plants of the class 

 are formed entirely of cellular tissue. But the Ferns are 

 highly organised, approaching Monocotyledons in some of 

 their features, and having; their leaves or fronds beauti- 

 fully veined. 



The parts of a Fern are — 1st, the root, which we can 

 easily recognise, being subject only to the variations 

 which we observe in the roots of other plants. It has a 

 rhizome, which generally creeps upon or under the 

 ground, and might easily be mistaken for the root ; and 

 then in tree Ferns there is the bole or stem, which is 

 called a stipe. The leaf of the Fern is called a frond ; 

 and the frond is composed of a main stalk (rachis), and 

 leaflets (pinno?.) It has no flowers, and its seeds or spores 

 grow abundantly on the back of the frond. The spores 

 are enclosed in cases, which form masses called sort, or 

 spore-masses. From the form and position and cover- 

 ing of these spore-masses the genera of Ferns are decided. 

 The first division of Ferns, the Polypodiaceae, have the 

 seed-cases in round masses, without any covering. 



