100 AN INTRODUCTION 



CHAP. XXVII. 



OF THE TWENTY-FOURTH CLASS CRYPTOGAMIA*. 



/ 



THIS Class consists of such plants as conceal their 

 fructification, having their flowers either within the 

 fruit, or so small, as not to be perceptible to the 

 naked eye. The fructification in these is also of an 

 uncommon structure. The orders are four, viz. 



ORDER L Filices, Ferns, comprehending such 

 plants as are dorsiferous f. What is known of the 

 fructification of these plants amounts only to the few 

 characters following. 



Characters of the FILICES. 



CALYX A squama growing out of the leaf, open- 

 ing on one of its sides ; and under which there are 

 pendunculate globules ; each globule is girt with an 

 elastic ring, which breaks elastically, and sheds a dust, 

 which are the seeds. This order contains seventeen 

 genera, distinguished into, 1. Those plants whose 

 fructifications grow in a spike, of which there are 

 four, viz. Equisetum, Onoclea, Ophioglossum, and 



* The plants of this class are often of dangerous quality. 



t Bearing their fruit on the back of the leaf. These hav 

 been called also Ephiphyllospermous, a Greek compound ex. 

 pressive of the same circumstance; Capillary, as being esteem- 

 ed good for the hair ; and Acaules, without stems ; for in these 

 plants, what rises out of the ground is plainly a leaf only : 

 one of the characters of astern or trunk is to be alike on erery 

 side ; but in the stalks of ferns, there is manifestly a front and 

 back, the former being flat and channelled, and the latter con. 

 Tex, which shews them to be leaves. 





