CRYPTOGAMOUS PLANTS. 221 



Section IV. 

 Of Ferns. 



The Ferns have sometimes been called by the name 

 of Dorsiferous or Epiphyllospermous plants, making 

 allusion to one of their most striking characters, viz : 

 that their fructification arises in general upon the back 

 of their foliaceous organs, which may be considered 

 either as true leaves, bearing, by a structure peculiar to 

 this family, the organs of fructification, or as peduncles 

 bordered with foliaceous limbs. 



In favour of the first opinion, we may allege that these 

 foliaceous organs are not always fructiferous, and that 

 some Ferns bear their fructifications in spikes which seem 

 distinct from the leaves, that they present absolutely the 

 use and structure of true leaves, and are provided with 

 stomata ; that, lastly, there are some phanerogamous 

 plants, as Polycardia, where we find a somewhat similar 

 structure. 



We may say, in favour of the second opinion, that the 

 leaves without fructifying organs owe this state to an 

 abortion analogous to that of peduncles transformed into 

 tendrils or spines ; that the pretended spikes of certain 

 Ferns are only peduncles which are not bordered ; that 

 certain phanerogamous plants, as Urtica membranacea 

 and Paspalum membranaceum, present peduncles bordered 

 in a similar manner ; that if petioles can be bordered 

 with a foliaceous limb furnished with stomata, pedun- 

 cles can also present the same singularity ; and, lastly, 

 that the example of phanerogamous plants with epi- 

 phyllous flowers are all doubtful when closely examined. 



It is, perhaps, in order not to decide this question, that 



q 2 



