ORDERS. < i> 



CLASS 24, Cnjptogamia. 



Observation* The orders in this class are professedly natural. 

 They are four in Linnaeus, but we no,Y reckon live. 



1. FILICES, Ferns. Whose fructification is obscure, 

 and grows either on the back of the leaf, which is 

 thence denominated a frond ; or upon a separate frond. 

 Common Brake is an example. 



The parts of their flowers are almost entirely un- 

 known. Their fructification proved to be such by pro- 

 ducing them from their seeds, consists of the following 

 parts. 



1. Involucre, (i-nvolucrum or inducium.') PL 5, fig. 

 10. A membranous patch which covers the capsules. 



Observation. The fructification is most commonly in dots or 

 patches, which are frequently in rows upon the back of the leaf; 

 each of these dots or patches consists of an assemblage of cap- 

 sules, either naked or covered by an involncrum. 



2. Capsules, PL 3, fig. 11, which consist of two 

 valves, PL 3, fig. 11, 6. contain many seeds, and are 

 sometimes furnished with a ring. 



3. Ring, (annulus.} PL 3, fig. 11. a. An elastic sub- 

 stance which surrounds the capsule, partially attached 

 by its opposite ends to the two valves of the capsules. 



When the capsule is ripe, its valves separate, and the 

 ring, by its elasticity, throws it open, thus scattering 

 abroad the seeds. 



Observation. Those furnished with a ring are termed annulate, 

 those destitute of it, exannuJatx. 



2. Musci, Mosses. These are really herbs, with dis- 

 tinct leaves, and frequently a distinct stem. 



Fructification of the Mosses. 



The fertile flowers have the following parts. 



1. Calyptra, (cahjptra.} PL 3, fig. 14, b. The" 

 proper calyx of the mosses, the summit of which per- 

 forms the office of a stigma. See page 49. 



Observation. Smith considers this a species of corolla, and its 

 apex, a stigma. 



