FERNS. CHAP. I, 



it is lash-shaped and creeping, though sometimes 

 erect at the extremity. But in most of them, that 

 is in the frond bearing Ferns, the trunk, if trunk it 

 can be called, is a stipe supporting the frond, if it is 

 not rather to be regarded as the base of the frond 

 itself, and the plant altogether stemless. In Poly- 

 podium Dryopteris it is long and slender, if com- 

 pared with the upper part of the frond ; in Poly- 

 podium calcareum it is short ; in Asplenium Tri~ 

 chomanes it is cylindrical ; in Pteris aquilina it is 

 flattened on the one side ; in Adiantum Capillus 

 Veneris the surface is smooth ; and in Aspidium 

 Filiv-mas it is chaffy or beset with scales. 



JModifi- The Branch. Ferns, in general, are not furnish- 

 cations. e( j w j t k an y p art t j lat can correct ]y fc e ca ]l e( l a 



branch ; though some Ferns are furnished with 

 parts which are generally designated by that name. 

 I believe they are peculiar to the genera Equisetum 

 and Lycopodium; in the former of which they issue 

 from the stem in whirls situated at regular intervals, 

 and are in their structure similar to that of the stem 

 itself, as being composed of a succession of dis- 

 tinct and tubular pieces inserted into one another. 

 In the latter they do not originate in any regular 

 order, but are also in their structure similar to that 

 of the stem. 



Figure and The Leaf. The leaf, like the branch, is not in 



tion! b general to be found in the tribe of the Ferns, at least 



as a separate and distinct organ. But leaves are to 



be found in the genus Lycopodium) in which they arq 



