60 
MIMULUS SMITHII. 
the slender stems ; and the use of them, as Dr. 
Wallich remarks, is probably “ to form 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. In this case they ate necessary, 
on account of their long, slender, twining stems 
being too narrow a channel of supply from the 
subterranean roots to the leaves.” 
The Macgraavia also have little pitchers 
occupying the place of bracteae, which either 
hang down or stand erect among the flowers 
but, together with the last, are very differently 
constructed from the Nepenthes and Sari'a- 
cenia . Amongst these hollow-leaved plants, may be placed the Dipsaaus fullonum, 
which forms at the axillae of the leaves a kind of basin, usually containing a quantity 
of water, which becomes the grave of a multitude of insects. The water had once 
the reputation of being a beautifier of the skin, but is now little regarded. 
The preceding remarks are chiefly confined to some of the plants having peculiar 
appendages, attached either to their leaves or some other part of the plants, into 
which, being hollow and containing a liquid, insects of different kinds are, from some 
unknown motive, induced to enter, and from which, on account of certain impediments, 
they are totally unable to escape ; consequently, the hollow appendage becomes their 
grave : but whether their death is necessary to the well-being of the plant cannot be 
decided, and, therefore, the question 'must be for the most part left as we found it. 
The next plants in order are those which have the power of entrapping 
insects by the contractility or irritability existing either in the leaf or flower. 
Amongst those possessing irritability in their leaves, none are more remark- 
able than the Dioncea Muscipula , or Venus’s Fly-trap. This plant has jointed 
leaves, furnished on the edges with a row of strong prickles, and what is usually 
called the leaf is supposed by some to be the petiole, which is winged like that 
of the orange, so that it is the proper leaf which operates as the trap. Others, 
however, have thought that the winged petiole, or leaf-stalk, is the true leaf itself, 
and that the trap is merely an appendage ; this latter opinion, from the appearance 
of the plant in our possession, strikes us as being the most probable. There is a 
sweetness secreted in glands on the surface of the trap, which appears to attract 
flies ; and no sooner do they venture to settle on its surface, than the sides of the 
leaves spring up after the manner of a rat-trap, and locking their rows of prickles 
together, squeeze the insects to death ; after which it again expands. Linnaeus and 
others thought, that if the insect ceased to struggle, the leaf would open and 
