308 Prof. Ch. Morren on the Morphology of the Ascidia, 



author does not explain the genesis or the morphology of 

 these aquiferous organs. 



M. Link proposes quite a different system. He first lays 

 down this principle, that the blade of a leaf is never developed 

 after the petiole, but always before (nunquam lamina post pe- 

 tiolum, sed semper ante ipsum explicatur), which I shall take 

 the liberty of denying ; for if we observe the development of 

 the leaves with large reniform blades of Hydrocharis morsus- 

 ran<B, we shall see precisely the contrary ; the petiole is first 

 developed without a trace of blade and sometimes becomes 

 more than a foot long, then at its free extremity it expands at 

 first into two auricles Avhich unite to form an oval ; this grows 

 larger and larger to elongate finally into a great kidney- 

 shaped blade. There the subsequent origin of the blade is a 

 thing quite evident. I have also observed it on Sagittaria 

 sagittifolia, &c. M. Link however, setting out from this fact 

 as from an incontestable principle, afterwards observes, that 

 in Nepenthes the leaves have at first no ascidia which origin- 

 ate subsequently ; and he further remarks, that the inferior 

 leaves are without the ascidiferous petiole, which is only pre- 

 sent on the upper leaves. He thus takes the lanceolate organ 

 which terminates the lower part of the ascidiferous apparatus 

 of Nepenthes for a true leaf, and the pitcher with its cirrhose 

 support appears to him to be an appendix of the inflorescence, 

 which is confirmed in his opinion by what happens in the 

 bracts of Norantea (Ascium*). This idea of comparing the 

 pitcher to a floral organ, of reducing its origin to a state of the 

 flower, appears to me a first step towards the correct appre- 

 ciation of the true nature of the ascidium. This is the state 

 of the discussion between the principal English, French, and 

 Prussian botanists who have treated of organography at the 

 present period. I cannot agree with them, however great in- 

 fluence their authority may have upon my opinions. In the 

 first place, there is a great difference between the ascidium of 

 Nepenthes and those of Sarracenia, Upon Nepenthes distilla- 

 toria as upon N cristata, two species which I have before me, 

 the moveable lid is articulated and its system of nervation 



* Elemcnta Philosophiae Botanicse, 1837, vol. i. p. 474. § 115. 



