LECT. HI,] CELLULAR TEXTURE. 73 



the light obliquely thrown upon it, it appears 

 iridescent ; but, as it has been already stated, 

 its organization is too minute to be determined 

 by any magnifying power with which we are ac- 

 quainted. When put into water it is very quickly 

 reduced to a kind of mucilage. This solution, 

 however, takes place only when the vitality of 

 the part is extinct ; for, the cells in the living 

 plant are often turgid with aqueous fluids, and 

 yet they retain their proper consistence and 

 form. 



The cellular texture, in one form or another, 

 enters into the composition of almost every vege- 

 table organ. It is dry in some parts, but in other 

 situations it receives and slowly transmits fluids ; 

 and in it, principally, the various secretions of the 

 plant are deposited. Thus, it is generally filled with 

 mucilaginous, resinous, oily, and saccharine juices; 

 but sometimes the cells contain only air. In the 

 bark of plants the cellular texture is found imme- 

 diately under the cuticle, filled with a resinous juice, 

 which is of a different colour in different species of 

 plants, but most frequently green. In this situa- 

 tion it is the seat of the colour of the bark, in the 

 same manner as the rete mucosum, or, more pro- 

 perly, the reticulated capillary membrane situated 

 under the human cuticle, is supposed to give the 

 colour to the skin ; the reddish white in the Euro- 

 pean, and the black in the African. The cells 



