272 DECOMPOSITE ORGANS. CHAP. I. 



of the dissector beyond that of a few bundles of 

 fibres dispersed throughout a pulpy parenchyma, and 

 enveloped by a bark or epidermis. But when the 

 flower has once fallen, and the ovary attained to its 

 utmost magnitude, and the fibres and parenchyma 

 of the peduncle have begun to become firm and 

 woody, the fruit begins also to assume a mature and 

 ripened aspect, and gradual change of consistence ; 

 exhibiting its last degree of developement and 

 solidity, and consisting of the pericarp and enclosed 

 seed. 



SECTION IV. 



The Leaf -stalk and Leaf. 



Composed THE Leaf-stalk, or petiole supporting the leaf, 

 epidermis 1 , which is a prolongation of the branch or stem, or 

 EmfdleTof rat ^ er a P art i a l ste m attached to it, exhibits upon 

 longitudi- dissection the same sort of structure as the pedun- 



nal fibres. . 



cle namely, an epidermis, a pulp or parenchyma, 

 and bundles of longitudinal threads or fibres. 



The Epidermis, which is a thin and fine membrane, 

 discovers when detached the enclosed parenchyma 

 and interspersed fibres, which are generally in three, 

 five, or seven sets, appearing like round transparent 

 points upon a transverse section, or like thick and 

 strong threads upon a longitudinal section ; being 

 always most distinguishable at the base, where they 

 occasion a considerable protuberance ; and occupy- 

 ing in their distribution a line forming a circle, or a 



