196 Scientific Intelligence. — Botany. 



ject of the watery secretion of the leaves of plants. The Ne- 

 penthes, Sarracenia, and Cephalotus have long afforded the 

 most striking examples of this function. Rumple's observation, 

 that the water of the tankard-shaped leaves of the N. distillatoria 

 is always pure, militates against the supposition that it comes 

 from without. He also remarked, that when the hd of the N. 

 Phyllamphora is open, the water is diminished one-half by solar 

 evaporation, which, however, is restored at night. The struc- 

 ture of the goblet-like leaf, as observed by Treviranus, is like an 

 actual secreting organ, and adds a strong reason for thinking that 

 the plant supplies the water. He finds the parietes of the leaf of 

 N. distillatoria traversed by a multitude of proportionably large 

 anastomosing veins, which contain many true spiral vessels. 

 The upper half of its inner surface is covered with a blue rind, 

 as parts are often which are to be protected from the action of 

 water ; the under half is, on the contrary, shining and full of 

 gland-like eminences, directed downwards, and having a hole 

 almost visible with the naked eye, which is uncovered with the 

 cuticle, which the remainder possesses. Through these, he 

 thinks, is the water secreted, and it reaches generally to their 

 level in the middle of the leaf. It is remarkable, that the inner 

 or under surface of the lid, exhibits a similar structure, but 

 whether it also secretes water, future observations must discover. 

 Sir J. Smith''s remarks on the construction of the lid of the Sar- 

 raccenia flava and adunca, are sufficient to invalidate Linnaeus^ 

 opinion, that the leaves of this genus, as well as the Nympheae, 

 were intended as natural reservoirs for rain-water. In the Sar- 

 racenia, there is no particular apparatus as in the Nepenthes, 

 for the secretion. Macbride's observations demonstrated on the 

 edge of the Sarracenia adunca, a sweet substance that allures 

 insects, which, creeping into the funnel of the leaf, arrive at the 

 water, and being hindered from returning by the hairs directed 

 downwards, are drowned. It is reserved for future investiga- 

 tion to discover what gives the sweet taste to the Nepenthes and 

 Cephalotus, which is mentioned, and how the insects are killed, 

 as nothing appears to hinder their creeping out again. Trevi- 

 ranus has examined particularly the watery secretion of the 



Amonium Zerumbet, which was not noticed by any botanist, 



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