The Scranton tribune. [volume] (Scranton, Pa.) 1891-1910, 1897-03-20
MANYsPLANTSgTHAT
SHOW INTELLIGENCE
Evidence to Prove That They Think for
Themselves.
CURIOUS PAGE OF NATURAL HISTORY
From Fern spores and Pot Mold to
Mangroves and MisletOe, the Mar
vellous Powers of Life Choice Are
shown.
from the Pharmaceutical Journal.

Plants, Just as much as animals, arc
irritable beings. and like animals they
may show irritability to varying de-
grees. Thus some plants may he de-
scribed as mildly irritable, others as
rapidly irritable, and few as even rest
lessly irritable Every plant has to
look after it's feeding. Green plants,
Furthermore. have to seek for very
important part of their food in the air,
and this they take up under the intiu-
ence of light. so that it is not surprising
to find the influence of environment
making itself felt on every plant. and
causing the plant in one way or another
to react to its surroundings. 1t is the
particular response to stimuli which we
may call irritability. a plant is irrit-
able because it is able to respond.
Take the case of Vaucheria, lowIy
organized plant frequently found form
ing large dark patches is put into water
it begins to change its character alto
gether, and in the tips of its tilaments
aggregatiOns of protoplasm are seen to
form. These become more and more
dense, the filament then bursts anC dis
charges q green protoplasmlc mass,
which Swims by means of ella, ana mn
ally settles down, The motile plantlet
does not do this indiScrminately or in
hurry, but shows great method IN
settling down. Before coming to rest,
each little protopiasmic body mas
thought for itself, and has decided to
settle on the basin a little way below the
surface of the water. In this position 1t
secures the maximum amount OF hght
which is to enable it to make the sub
stance it requires for it's growth. We
may say. then, of this spore that it has
had to nunt for its food and finally set
tied down on a suitable spot.
Higher plants no less than lower are
irritable The shoots of a tree, respond
ing to the influence of light, place the
leaves in the most advantageous posi-
tion for the work they have to perform,
and the roots, in obedience to the stimu-
lus eXerted by gravitation grow down
ward INTO the earth. Tendrils are modi-
fed leaves or branches which have be-
come irritable to contact.
AN IRRITABLE PLANT.
A little plant, the ivy-leaved toad
flax, found covering limestone walls,
with tufts of bright green foliage and
purple flowers, affords an interesting
instance of irritability. When in bios
som, the long flower stalks of the plant
turn outward and carry the flowers
from underneath the leaves, in order
that they may secure the visits of in
sects, which are necessary for their
fertilization. The stalk of the seed VeS-
sci is fortunately for the welfare of the
plant, an irritable structure. When flow
ering is over ii no longer seeks the place
which is most strongly lighted, but car
ries the rpenng fruit behind the leaves
into a little Granny Of the wall. Here
the seed vessel bursts and discharges It's
contents, not among coarser weeds.
Where it's growth would be inevitably
checked, but upon the soil which has
collected in the Granny. Young seed
lings soon make their appearance, ana,
as a result of this flouriShlng start III
llfe the ivy-leaved toad-fiaX is usually
found abundantly in districts where it
is found at all. Here we have a flower
stalk responding to the stimulus of
light, and a reversal of the influence at
different periods of development en-
abllng the plant to accommodate ltsell
to its environment.
All plants only succeed so long as
their irritability leads them to adapt
themselves to their surroundings. The
more lowy organized, by reason OF thelt
simpler structure, show greater versa
tility in this respect than their more
complex relatives. 1t is easy to under
stand how a mass of protoplasm can
more readily adapt itself to varying
conditions than a higher plant with It's
extensive differentiation of tissue.
Bacteria are especially sensitive from
this point of view. They can dlstln-
guish with very great nicely between
the relative suitability of two nutrient
solutions. Many of them are capable OF
perfectly astounding discrimination II
this respect. In the same way the Whlte
blood corpuscles are attracted by GER
tain foreign-often pathogenic-sup
stances to the spot of the intrusion o
bacteria into the blood. Here IL Is INT
business of the white corpuscles, If pos
sible, to destroy the bacteria. This at
traction shown by many organisms to
ward chemical substances is known "a
chemiotaXiS.
FURTHER EVIDENCE.
The spores of ferns and mosses affor'
remarkable illustration. The mali
cells are discharged by the plant, anC
may be seen swimming in all direction
in water, when suddenly they will max
dash in the direction of the female or
gan. This sudden rush is a chemiotac
tic phenomenon. In the case of fern
malic acid, and in the case of MOSES
sugar, is the substance secreted by tn
female organ, causing the surprising ac
tivity of the little swimming anthero
zoidsS Wonderfully dilute solutions ar
capable of causing the stimulus. Sup
posing the strength of the solution b
gradually increased, the limit is short
ly reached, beyond which the solutio
acts as a repellent instead of an at
tractive stimulus, causing the plants t
swim away as far as they can. If, how
ever the plants be compelled to live i
a. strong solution, they will in time ge
acclimatiZed and viii swim vigOrousl
toward solution of the attracting sal
although it may very much exceed tn
normal maximum of attractn
strength.
The following IS an example of chem
utaXis which a plant has discovered I
secure its own ends. Isaria is a fungi
which infests silk-worm and other ce
terpillars. Melanospora is another fun
gus parasitic upon isaria, an eXtremel
intelligent parasite, and unless it hal
pens to meet with filament of isaria
entirely misses it's vocation. Now mt
lanospora apparently secretes SON
substance which exercises considerab
attraction for isaria filaments, for the
seek out the apparently harmless sport
of melanospora and grow freely owe
them. When the spore is surrounde
by isaria filaments, ii puts out its ger
tube and proceeds to feed upon i
host.
Not so obviously intelligent althous
II Is in reality, is the life of the gree
plants. The fact that the branches
a tree grow upward into the air an