214 CRYPTOGAMIA. 



fore been distinguished by late writers under the name of 

 Fhwerless Plants. 



This class is divided into eight orders, or tribes, viz. 

 I FILICES, (Ferns,) 2. EQUISETACE^E, (Horsetails,) 3. 

 LYCOPODINE,E, (Club-mosses,) 4. Musci, (Mosses,) 5. HE- 

 PATIC/E, (Liverworts,) 6. ALG.E, (Flags,) 7. LICHENS, 

 (Rock Mosses,) 8. FUNGI, (Mushrooms.) 



These divisions will be explained and illustrated in their 

 turn ; but we must first explain a few terms, which are em- 

 ployed only in describing plants of this class, and which 

 therefore have not been heretofore used. 



Sori, patches of fructification on the back of the fronds, 

 or leaves of Ferns. 



Sporules, the seeds of flowerless plants, or rather the parts 

 of these plants which answer to the seeds of other plants. 



TheccB, the cases which contain the sporules of Cryptoga- 

 mic plants, answering to the seed vessels of other plants. 



Gregarious, herding together, as when the stripes of several 

 Mushrooms spring from the same place. 



Calyptra, literally an extinguisher ; applied to the body 

 which tips the thecae of the Mosses. 



Indusium, the membrane that encloses the thecae of Ferns. 



Cap, the head or spreading part of Mushrooms. 



Gills, the lamella, or thin vertical divisions on the under 

 side of the caps of Mushrooms. 



ORDER I. FILICES. Ferns. 



In this order the fruit is mostly placed on the back of the 

 frond ; the thecae are naked. When young, the fronds are 

 circinate, or curled. 



The principal distinction which exists between Ferns and 

 other flowerless plants is found in the situation of their sori, 

 or patches of sporules, which in most cases are inserted on 

 the back of the frond, Sometimes they appear only in the 

 form of little spots, and sometimes they cover the whole 

 under surface, contracting the leaf, and giving it the appear- 

 ance of one mass of fructification. The thecae, or patches 

 of sori, are surrounded by elastic rings, which in some spe- 

 cies burst as they become dry, and throw the sporules, or 



What are sori ? What are sporules ? What are the thecae of Cryp- 

 togamous plants ? When are plants said to be gregarious ? What are 

 calyptra? What is meant by indusium? What part of a mushroom is 

 the cap, and what part the gills ? On what part of the plant do the fernt 

 bfekr their fruit * 



