In his third lecture delivered, on the 25th February 1913, at the Punjab
University Hall, Dr. Bose of Calcutta dealt with "Plant Response." He
said:--
In strong contrast to the energetic animal, with its various reflex
movements and pulsating organs, stands the plant, in its apparent
placidity and immobility. Yet that same environment which with its
changing influences affects the animal is playing upon it also. Storm
and sunshine, the warmth of summer and the frost of winter, drought and
rain, all these come and go about it. What coercion do they exercise
upon it? What subtle impress do they leave behind? These internal
changes are entirely beyond our visual scrutiny. Is it possible in any
way to have these revealed to us? Dr. Bose had shown the possibility of
this by detecting and measuring the actual response of the organism to a
questioning shock. In an excitable condition the feeblest stimulus
should evoke in the plant an extraordinarily large reply in a depressed
state even a strong stimulus would only call forth a feeble response;
and lastly, when death overcome life, there would be an abrupt end of
the power to answer to all. By the invention of different types of
apparatus, the lecturer had succeeded in making the plant itself write
an answering script to a testing stimulus. Scripts could also be
obtained of the plant's spontaneous movements; and a recording arm
demarcated the line of life from that of death.
In taking the self-made records made by the plant it was found that
after the prolonged inactivity of a cold night the plant was apt to be
lethargic, and its first answers indistinct. But as blow after blow was
delivered, the lethargy passed off, and the replies became stronger and
stronger. After the fatigue of the day, the state of things was
reversed. The plant became very lethargic after excessive absorption of
food; but the normal activity might be restored by artificial removal of
the excess. The effect of alcohol and of various narcotics were clearly
followed in the modification of the automatic record made by the plant.
A prevailing scientific error had overcome in life, there would be an
abrupt end regarding a certain class of plants to be alone sensitive.
The lecturer showed by certain remarkable experiments that all plants
and all organs of plants were sensitive.
In certain animal tissues, a very curious phenomenon was observed. In
man and other animals there were tissues which beat spontaneously. As
long as life lasted, so long did the heart continue to pulsate. There
could be no effect without a cause. How then was it that these
pulsations became spontaneous? To this query, no satisfactory answer had
been forthcoming. Similar spontaneous movements were also observable in
plant tissues, and by their investigation the secret of automatism in
the animal world became unravelled. The existence of these spontaneous
movements could easily be demonstrated by means of the Indian "Bon
Charal", the telegraph plant, whose small leaflets danced continuously
up and down. The popular belief that they danced in response to the
clappings of the hand was quite erroneous. From the readings of the
scripts made by this plant, the lecturer was in a position to state that
the automatic movements of both plants and animals were guided by laws
which were identical. Thus in the rhythmic tissues of the plant and the
animal the pulsation frequency was increased under the action of warmth
and lessened under cold, increased frequency being attended by
diminution of amplitude, and "_vice versa_". Under ether, there was a
temporary arrest, revival being possible when the vapour was blown off.
More fatal was the effect of chloroform. The most extraordinary
parallelism, however, lay in the fact that those poisons which arrested
the beat of the heart in a particular way arrested the plant pulsation
in a corresponding manner. The lecturer had succeeded in reviving a
leaflet poisoned by the application of one with a dose of counteracting
poison.
A time came when after one answer to a supreme shock there was a sudden
end of the plant's power to give any response. This supreme shock was
the shock of death. Even in this crisis, there was no immediate change
in the placid appearance of the plant. In man at the critical moment, a
spasm passed through the whole body, and similarly in the plant the
lecturer had discovered that a great contractile spasm took place. This
was accompanied by an electrical spasm also. In the script of the death
recorder the line that up to this point was being drawn became suddenly
reversed, and then ended. This was the last answer of the plants.
Thus the responsiveness of the plant world was one. There was no
difference of any kind between sunshine plants, and those which had
hitherto been regarded as insensitive or ordinary. It had also been
shown that all the varied and complex responses of the animal were
foreshadowed in the plant. An impressive spectacle was thus revealed of
that vast unity in which all living organisms, from the simplest plant
to the highest animal, were linked together and made one.
--_Amrita Bazar Patrika_, 5-3-1913.