3G ORGANOGRAPHY. BOOK I. 



CHAPTER II. 



OF THE COMPOUND ORGANS IN FLOWERING PLANTS. 



Having now explained the more important circumstances 

 connected with modifications in the elementary organs of 

 vegetation, the next subject of enquiry will be the manner in 

 which they are combined into those masses which constitute 

 the external or compound organs, or in other words the parts 

 that present themselves to us under the form of roots, stems, 

 leaves, flowers, and fruit, and that constitute the apparatus 

 through which all the actions of vegetable life are performed. 

 In doing this, I shall limit myself in the first place to Flower- 

 ing Plants [Introduction to the Natural System, p. 1.) ; reserv- 

 ing for the subject of a separate chapter the explanation of 

 some of the compound organs of Flowerless plants {ibid. 

 p. 307.), 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 Cuticle. 



Vegetables, like animals, are covered extei-nally by a thin 

 membrane or cuticle, which usually adheres firmly to the cel- 

 lular 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 reticulated character. 

 In some of the lower tribes of plants, consisting entirely of 

 cellular tissue, it is not distinguishable, but in all 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 



