ady to go on with their vivifying operations as they were in
behalf of the animals. There are some plants which seem not to be left
to the chances of securing their nourishment from the carbonate of
ammonia that the air and the soil contain, but are contrived so as
to entrap living animals and hold them fast while they undergo
decomposition, so that all their gases may be absorbed by them alone.
Thus, "the little Sundew exudes a gluey secretion from the surface of
its leaves, which serves to attract and retain insects, the decay of
whose bodies seems to contribute to its existence." And the Dionaea,
or Venus's Fly-trap of the Southern States, has some leaves which fold
together upon any insect that alights upon their upper surface; and by
means of a row of long spines that fringes the leaves, they prevent his
escape. The more active the struggles of the captive, the closer grows
the hold of the leaf, and speedily destroys him. The plant appears to
derive nutriment from the decomposition of its victims. "Plants of this
kind, which have been kept in hot-houses in England, from which insects
were carefully excluded, have been observed to languish, but were
restored by placing little bits of meat upon their traps,--the decay of
these seeming to answer the same purpose."
The four elements already referred to are by no means all the material
ingredients of animal bodies. There are, also, phosphorus, lime,
magnesia, soda, sulphur, chlorine, and iron; and if you believe some
chemists, there is hardly a mineral in common use that may not be found
in the human body. We doubt, however, whether lead, arsenic, and silver
are there, without the intervention of the doctor.
What becomes of the phosphorus and the rest, when an animal dies? Oh,
they take up new business, too. They are as indispensable to the animal
frame as the four most prominent ingredients. We eat a great deal of
bread and meat, and a little salt,--but the little salt is as important
to continued life as the large bread. There is hardly a tissue in the
body from which phosphorus, in combination with lime, is absent; so that
the composition of lucifer-matches is by no means the most important
use of this element. The luminous appearance which some putrefying
substances, particularly fish, present at night, is due to the slow
combustion of phosphorus which takes place as this element escapes into
the air from the decomposing tissues.
The necessity for the steady su
|