132 CUTICLE EPIDERMIS. [BOOK i. 



CHAPTER II. 



OF THE COMPOUND ORGANS IN FLOWERING PLANTS. 



HAVING thus explained the more important circumstances 

 connected with modifications in the elementary organs of 

 vegetation, the next subject of inquiry must be the manner 

 in which they are combined into those masses which con- 

 stitute the external or compound organs, or in other words 

 the parts which present themselves to us under the form 

 of roots, stems, leaves, flowers, and fruit, and which consti- 

 tute the apparatus performing all the actions of vegetable 

 life. In doing this, I shall limit myself in the first place to 

 Flowering Plants (Vegetable Kingdom, p. 4.) ; reserving for the 

 subject of a separate chapter some explanation of the com- 

 pound organs of Flowerless Plants (ibid.), which differ so 

 much in structure from all others, as to require in most cases 

 a special and distinct notice. 



SECT. I. Of the Cuticle and its Appendages. 



1. Of the Epidermis. 



VEGETABLES, like animals, are covered externally by a 

 thin membrane or epidermis, which usually adheres firmly to 

 the cellular substance beneath it. To the naked eye it 

 appears like a transparent homogeneous skin, but under the 

 microscope it is found to be traversed in various directions 

 by lines, which, by constantly anastomosing, give it a reticu- 

 lated character. In some of the lower tribes of plants, con- 

 sisting entirely of cellular tissue, it is not distinguishable, 

 but in others it is to be found upon every part exposed to 

 the air, except the stigma and the spongelets of the roots. 

 It is, however, as constantly absent from the surface of parts 

 which live under water. Its usual character is that of a 



