124 Proceedings of the 



It was suggested that pitchers have doubtless different uses in 

 different plants. In the Dischidias it is probable, as Dr. Wallich 

 has remarked, that they are reservoirs of nutriment, from which the 

 roots, emitted by the stem, and constantly found ramifying within 

 them, absorb food for the general support of the individual, and that 

 in this case they become necessary in consequence of their long 

 slender twining stem being too narrow a channel of supply from 

 the subterranean roots to the leaves. With regard to Nepenthes, the 

 following idea of the uses of its pitcher was offered for consideration. 

 It has been discovered by Mr. Valentine, that a vast quantity of 

 spiral vessels is found in the stem and petioles, a quantity so con- 

 siderable that no plant has yet been noticed in which they are 

 equally abundant; now it has been ascertained by Bischoff, that 

 spiral vessels convey air containing about twenty-eight per cent, of 

 oxygen ; and as it is well known that an accumulation of, or an 

 excessive supply of, oxygen is destructive to vegetable life, is it not 

 possible that the pitchers are a contrivance to enable the plant to 

 get rid of its oxygen, and may not the water that they contain have 

 been discharged by the spiral vessels themselves ? It was submitted 

 that a confirmation of this opinion was apparently afforded by an 

 observation of the late Dr. Jack, that the bottom of the pitchers of 

 the Penang species, in the inside, is beautifully punctured, as if by 

 the mouths of vessels ; and also by a remark of Dr. Graham, that 

 the water in the pitchers formed in the Botanic Garden, Edinburgh, 

 was at first subacid, and continued to increase in acidity till the 

 whole evaporated. 



It was stated that scarcely anything was, however, known of the 

 exact nature of the water in pitchers ; it having been only analyzed 

 in one instance, when Dr. Turner found the contents of Nepenthes to 

 contain minute crystals of superoxalate of potash. It is well known 

 that in Sarracenia the water is putrid ; and in Norantia it is de- 

 scribed as sweet in one species, and bitter in another. 



The last subject of inquiry was the nature of the pitchers, and 

 their analogy to the other and more common organs of vegetation. 

 With reference to this point, some remarks were made upon the 

 doctrines of morphology, a subject first distinctly adverted to in this 

 country, incidentally and in a very concise manner, by Mr. Brown, in 

 1816, but originally conceived by Jungius in 1678, and subsequently 

 explained in an admirable treatise by the celebrated poet Goethe 

 in 1790. The sum of this doctrine is, that a plant usually consists 

 of only two essentially different parts, viz., the axis (or stem and 

 root) and the appendages of the axis, all of which, under whatever 

 form they may appear, whether of bracteae, calyx, corolla, stamens, 

 or fruit, are mere modifications of leaves. Consequently, it should 

 follow that pitchers are also leaves ; an opinion that was supported 

 in Sarracenia by a reference to their evident transition from the 

 form of leaf in Dioneea Muscipula, the pitcher itself being a petiole 

 in a particular state, and the lid the lamina ; in Nepenthes and 



