416 JOURNAL OF SCIENCE 
In damp localities in North Carolina an ally of the Drosera is to 
be found, in which this specialization of function is carried to the 
highest extreme. This plant is termed Venus’ fly-trap or Dionea 
muscipula. The glands are not placed all over the leaves or stems as 
in Drosera, but are confined to the upper surfaces of the leaf blade. 
On each lobe of these leaves are placed three pointed processes, which 
are extremely irritable to a touch. The margins of the leaves are 
prolonged into sharp, rigid spines, so placed that when the lobes 
close, they lock like the teeth of a rat-trap. The slightest touch 
causes the lobes to close rapidly, but—like Drosera leaves—no amount 
of blowing or shaking or dropping water on them will cause them to 
act. If an insect alights on the brightly-coloured leaf, and touches a 
spine, the leaf instantly closes, but to save waste of time as it were, it 
exhibits a singular contrivance. The interlocking marginal teeth do 
not close very tightly at first, so that if the insect be a very minute 
one, not worth the trouble of digesting, it readily finds a mode of 
exit. But if too large to escape, the lobes press closer and closer on 
it, the glands pour out their secretion on the unfortunate victim, and, 
in the course of two or three days, according to its size, all the soft 
parts of the body are dissolved away. Perhaps nothing in the vege- 
table kingdom shows such remarkable development as this plant, and 
it is certainly a singular fact that but for the discovery of its 
remarkable powers, it would probably have soon become extinct. We 
might have expected that so strangely developed a plant would have 
been very common, possessing as it does such contrivances to get food 
easily, but on the contrary, it is both yery rare and extremely limited 
in its distribution. All plants which have acquired carnivorous 
properties tend to have small roots, and to be more or less aquatic in 
their habitat. Most of them, too, have lost to a greater or less extent 
their power of decomposing the carbonic acid of the air, that is to 
say, that their leaves do not contain as much chlorophyll as ordinary 
green leaves, and they depend for their nutriment very largely on the 
adventitious supplies which they can catch. In this respect they 
resemble some of the parasites which depend also on ready-made food 
materials, and in both cases a very special line of development appears 
to be correlated with a comparatively precarious tenure of life. 
I have, hitherto, confined my remarks chiefly to the modifications 
and developments undergone by leaves; I will now, shortly, point out 
some of the modifications undergone by stems. The primary function 
of the stem appears to be simply that of support. It is the part of 
the plant which bears the leaves, flowers, and fruits, and enables the 
former to be borne upwards where they may receive the much-desired 
sunlight. It also acts as the conduit whereby the nutritive fluids are 
borne to all parts, and is frequently a store place for starch and 
similar reserve products. But all plants have not retained, what we | 
may consider the original condition, that, namely, of standing up. 
Most erect stems require to develope a considerable amount of woody 
tissue for the mere purpose of standing up, and it is evidently a 
modification of this form, when we find any plants doing without it. 
It must be remembered that the mass of the tissue in an erect stem 
is dead tissue, dead that is in the sense that it has no further power 
of development, and is only of use for support. Hence, if a plant can 
manage to get a sufficient quantity of sun-light for its leaves without 
