SECT. VI. THE CAUDEX. 287 



SUBSECTION I. 



The Caudev an Homogeneous Mass. The first 

 general mode of the internal structure of the 

 caudex is that in which an epidermis encloses 

 merely an homogenous mass of pulp or slender 

 fibre, that forms the principal body of the caudex, 

 and becomes somewhat indurated with age, though 

 not woody, without discovering any further variety 

 of component parts. This is the simplest mode of 

 internal structure existing among vegetables, as has 

 been observed by M. Mirbel in his Anatomy of 

 Plants, and exemplified in the lower orders of As exn- 

 frondose and imperfect plants, particularly the fhfalg* 

 Alga and Fungi, so that any one may easily satisfy and fungi ' 

 himself on the subject, as many plants of the above 

 tribes are extremely common, such as Lichen and 

 Tremella in the 'former, and Boletus, Agaricus, and 

 Clavaria in the latter. (PL VIII. Fig. 12.) 



Plants of this structure have seldom any distinct 

 or conspicuous root ; or if they have, it consists 

 merely of a few small fibres which are themselves 

 composed of an epidermis or bark containing a 

 tough and stringy thread. 



SUBSECTION II. 



The Caudex an heterogenous mass. The second 

 general mode of internal structure is that in which 



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