Nashville union and American. [volume] (Nashville, Tenn.) 1868-1875, 1875-08-08
INsECrIyOROUs PLAnTs.


been experimenting on the Drosera ro-
tRndJolia, or common sundew, since
1860, and has developed new and IN
teresting facts relating to the power Of
few well known plants to capture
many small insects, consume and d.
gest them, as appropriate and natural
! food. That animals subsist on plants
has long been known; but to reverse
the rule, and haze plants endowed with
something like the gastric juice in the
stomach Of animals, to digest and as
simulate flesh, is a newly discovered
function in vegetable physiology. To
show the reader how animal and vege-
table life and organization run into
each other, both ways, We copy a para
graph from Darwin's new book:
The gastric juice. OF animals contains,
as is well known, an acid or ferment,
both of which are indispensable for
digestion, and so it is with the secre-
ton Of DrOsers. When the stomach of
an animal is mechanically irritated it
secretes an acid, and when particles of
| glass or other such objects we're placed
on the glands Of Drosera the secretion,
/ and that Of the surrounding and I'M
/ touched glands, was increased IN guam
/ tity and became acid. But, according
/ to Shift, the stomach Of an animal does
not secrete its proper fermest, pepsin,
until certain substances, which
he calls peptogenes, are absorbed;
and it appears from my ex-
periments that some matter must be
/ lbsOrbed by the glands Of Drosera be-
fore they secrete their proper ferment.
That the secretion does contain a fer
ment which acts only in the presence Of
an acid on solid animal matter was
clearly proved by adding minute doses
1 Of alkah which entirely arrested the
| process of digestion, this Immediately
recommending as soon as the alkali was
neUtralized by little weak hydrochloric
/ acid. From trials made with a large
number Of substances 1t was found
that those which the secretion of Dro-
sera dissolves completely or partially,
OF not at all, are acted on In exactly the
same manner by gas .ric juice. We
may, therefore, conclude that the fer
ment # Drosera is closely analogous
to, or Identical with, the pepsin of
animals.
The plants secrete hydrochloric acid
for purposes Of digesting animal sub
stances, which acid is powerful enough
to dissolve bone and the enamel of
teeth, due, Mr.. Darwin believes, to the
desire Of the plant for phosphorus. In
the case Of bone, the ferment does not
come into play until all the phosphate
of lime has been decomposed and acid
Is present, and then the fibrous base Of
the bone is quickly dissolved. The Sc
cretion attacks and dissolves nuhitive
matter out Of living seeds. 1t also alb
serbs matter from pollen and fragments
Of leaves.
A long series Of experiments with
salts Of ammonia show that while they
all caused the tentacles and often the
blade Of the leaf to be infected, they
act with very different power, the cit
rate being the least powerful, and the
phosphate, owing, n doubt, 10 the
presence Of phosphorus and nitrogen,
being the most powerful. 1t was further
developed that the absorption of less
than the one-twenty millionth of a
grain Of the phosphate on the gland Of
the Drosera is sufficient to cause the
tentaele bearing this gland to bend to
the center Of the leaf.
These experiments have important
bearing on the use Of phosphates as
fertilizers IN all farming and gardening
operations. Productive industry and
the latest researches Of science meet
on common ground. Mr.. Darwin
says:
In this experiment, owing 70 the
presence Of cTystallation, less than the
one thirty millionth of a grain Of the
efficient elements could have been alb.
sorbed. There is nothing remarkable
IN such minute quantities being alb
sOrbed by the glands, for all physiolO-
gists admit that the salts CT ammonia,
which must he brought in still smaller
quantity by a single shower Of rain to
the roots, are absorbed by them. Nor
Is It surprising that DrOsera should be
enabled 10 profit by the absorption of
these salts, for yeast and other low
fungOid forms flourish IN solutions of
ammonia, if the other necessary ele-
ments are present. But 1t is an aston
ishing fact that so incOnceivably
minute a quantity as the one
twenty millonth Of a grain of
phosphate Of ammonia shou d IN
dUcc some change II a gland Of
Drosera sufficient to cause a motor I'M
pulse to be sent down the whole length
Of the tentacle; this impulse exciting
movement often through an angle Of
about $50 degrees. l know not wheth-
er to be most astyDished at this fact,
or that the pressure Of 4 minute bit Of
hair, supported 10y the dense secretion,
should quickly cause CONSPICUOUS move
4lELbs AAUA tDhGls LAlAD tALAtulC btuSl-
| tiveness, exceeding that Of the most
! delicate part Of the human body, as
well rs the power Of transmitting vari-
GUS impulses from one part of the leaf
10 another, have been acquired without
the Intervention Of any nervous system.
Here is a living being, q mere plant,
more sensitive without a nerve than
man with brain and nerves in the sup
posed greatest perfection. The organ
inns that feed on the sound and dis.
eased bodies Of mankind, may be not
not less at the head of organic life,
than at its base. In describing the
Venus fly trap, our author makes the
following interesting statement.
THE Venus fy-traps does not close
its lobcs for the falling ram, nor for
the wind, however severely it may blow;
nor did the heat from the rays of the
sun, concentrated by lens on the basis
Of several filaments, SO that they were
scorched and discOlored, cause any
movement, though the leaves were
active, as they closed, rather slowly,
however, when afilament on the opPos-
tie side was touched. Neutrality-suspicious.
matter C,,ob &c hits of wood cork