600 CONSERVATIVE ORGANS. [LECT. XI. 



and some others, have described the cuticular co- 

 vering of leaves as a simple body ; while M. de 

 Saussure*, Mr. Francis Bauer -}-, and M. De- 

 eandolle;}:, concur in the opinion which I main- 

 tain of its compound nature. Let us examine 

 the proofs upon which this is founded. 



The true epidermis, or the delicate pellicle 

 which forms the outermost covering of the leaf, 

 can be readily demonstrated in any small portion of 

 the cuticular covering carefully raised by the point 

 of a lancet, and placed in a drop of water under a 

 powerful microscope. In this small portion, taken 

 from a leaf of Dianthus Caryophyllus,\t isseen (a.40. 

 page 602) extending beyond the area of the meshes 

 (b. b.) of the interior cuticular layer, which are 

 seen through it, and is evidently a simple pellicle. 

 But Mr. Keith , who admits that it may be seen 

 in this manner, supposes that its individuality is 

 not proved by such a demonstration, as the meshes, 

 the intervals of which it might originally have filled 

 up, may be accidentally obliterated ; but, although 

 there is some plausibility in this objection, yet, 

 when we take this appearance in conjunction 

 with the double character observed in the trans- 

 verse section of the cuticular covering of every 



* Encyclop. Method, i. 67. 



f Tracts relative to Botany. 



I Mem. de I'Inst. Nat. i. 351. 



Syst. of Physiol Bot. vol. i. p. 313. 



