Prof. Ch. Morren on the Morphology of the Ascidia. 313 



lips has carried away that of the blade. Thus Sarracenia flava 

 represents the intermediate state ; there is a blade and the lips, 

 each half developed. Sarracenia variolaris has small lips and 

 a larger blade, and Sarracenia rubra has a large blade with- 

 out any lip. Moreover the same antagonism exists between 

 the struma and the lips ; in Sarracenia purpurea a struma 

 which occupies but the third of the aperture of the pitcher, 

 and great lips ; in Sarracenia variolaris a semi-struma and 

 small lips, and in Sarracenia rubra a struma almost circular 

 without lips. The Sarracenia flava deviates somewhat from 

 this law. 



From all these considerations it appears to me, 1st, that 

 since all the ascidimorphous bracts of Norantea and of Marc- 

 gravia are the blades of bracteal leaves joined at their mar- 

 gins so as to form hollow pitchers ; 2nd, that since the Di- 

 schidia Raffiesiana evidently presents leaves with the blade co- 

 hering to form an ascidium ; 3rd, that since in monstrous 

 states we see blades of leaves become ascidia, and that petioles 

 are not hollowed to produce this form accidentally, and that 

 when they are winged we do not see their wings cohere at 

 their free margins ; 4th, that since the structure of Sarracenia 

 proves very decidedly that it is a leaf which forms the asci- 

 dium, retaining the apex of the blade in its non-coherent state ; 

 5th, that since the ascidia of Nepenthes have already at the 

 lower part a winged petiole, and that the crests of their pitcher 

 are traces of foliaceous blades ; — it must be allowed that the 

 ascidia have, wherever they have been observed hitherto, a 

 similar organic composition, and that all are metamorphoses 

 of the leaf and particularly of the blade of this organ. 



It must be admitted that to give rise to this production na- 

 ture has folded in the blade of the leaf above, by uniting its 

 margins so that the upper surface of the organ becomes the 

 inner side of the pitcher ; that thus there is a great analogy 

 between a carpel and an ascidium, that this is invested with a 

 floral condition, that it has advanced a step further in organi- 

 zation, — but that with all these changes the functions remain 

 the same, because the anatomy of the organs has not been af- 

 fected, and that thus it was necessary that the ascidium should 

 secrete a fluid in its cavity ; as the nectary, another united or 



