me is _Bon charal_ or 'forest churl',
the popular belief being that it dances to the clapping of the hand.
There is no foundation however for this belief. It is a papilionaceous
plant with trifoliate leaves, of which the terminal leaflet is large,
and the two lateral, very small. Each of these is inserted on the
petiole by means of pulvinule. The lateral leaflets are seen to execute
pulsating movements which are apparently uncaused, and are not unlike
the rhythmic movement of the heart to which we shall see later that
their resemblance is more than superficial.

In the intact plant, under favourable conditions, these movements are
easily observed to take place more or less continuously; but there are
times when they come to a standstill. For this reason and because of the
fact that a large plant cannot easily be manipulated as a whole and
subjected to various changing conditions which the purpose of the
investigation demands, it is desirable, if possible, to experiment with
the detached petiole, carrying the pulsating leaflet. The required
amputation however may be followed by arrest of the pulsating movements.
But, as in the case of the isolated heart in a state of standstill, Dr.
Bose found that the movement of the leaflet can be renewed, in the
detached specimen, by the application of the internal hydrostatic
pressure. Under these conditions, the rhythmic pulsations are easily
maintained uniform for several hours. This is a great advantage, in as
much as in the undetached specimen, the pulsations are not usually found
to be so regular as they now become. So small a specimen, again, can
easily be subjected to changing experimental conditions, such as the
variation of internal hydrostatic pressure and temperature, application
of different drugs, vapours and gases.

Under varying conditions the same plant has been observed to take
different response times, as for instance, less in heat than in cold,
less in summer than in winter, less in the morning than in the evening,
and so forth. Again, different plants have different response times.

It is a remarkable fact that the mimosa is ten times as sensitive as a
frog in giving the response. And the native idea that plants are of a
lower order than animal life will cost many a sad disappointment.

In the course of his lecture Dr. Bose spoke of some of his startling
discoveries recently made.... The lecturer gave quite a spiritual turn
to his discourse as he finished it wi