12 



POPULAR GARDEN BOTANY. 



a warm part of the greenhouse, that they cannot be omitted 

 in a work devoted to exotics, a few of the genera and species 

 are therefore here described ; but it is strongly recommend- 

 ed that those who intend to devote some attention to this 

 class of plants, should procure the numbers, already out, of 

 a work entitled * A Natural History of Ferns, British and 

 Exotic/ by E. J. Lowe, Esq. ; when completed, it will com- 

 prehend all the Eerns which have been introduced into the 

 greenhouses and stoves of this country, with directions for 

 cultivation, and many other interesting particulars. The 

 following account of Eerns is to be considered only as an 

 introduction to this interesting subject. 



These plants have a stem either creeping below or in the 

 ground, or growing like a tree, having leaves which are 

 coiled up when young, either simple or divided in various 

 ways. The reproductive organs consist of spore-cases arising 

 from the veins upon the under surface of the leaves (or 

 fronds, as they are called) or from their margin; these 

 cases either have stalks in the form of an elastic ring, or 

 they are stalkless ; sometimes they arise beneath the cuticle 

 which then forms a cover for them, called an indusium ; or 

 they appear on the outer surface of the fronds. 



