ficulties in our path; first, to make the
plant itself consent to give its evidence; second, through plant and
instrument combined, to induce it to give it in writing. It is
comparatively easy to make a rebellious child obey: to extort answers
from plants is indeed a problem! By many years of close contiguity,
however, I have come to have some understanding of their ways. I take
this opportunity to make public confession of various acts of cruelty
which I have from time to time perpetrated on unoffending plants, in
order to compel them to give me answers. For this purpose, I have
devised various forms of torment,--pinches simple and revolving, pricks
with needles, and burns with acids. But let this pass. I now understand
that replies so forced are unnatural, and of no value. Evidence so
obtained is not to be trusted. Vivisection, for instance, cannot furnish
unimpugnable results, for excessive shock tends of itself to make the
response of a tissue abnormal. The experimental organism must therefore
be subjected only to moderate stimulation. Again, one has to choose for
one's experiment a favourable moment. Amongst plants, as with ourselves,
there is, very early in the morning, especially after a cold night,
certain sluggishness. The answers, then, are a little indistinct. In the
excessive heat of midday, again, though the first few answers are very
distinct, yet fatigue soon sets in. On a stormy day, the plant remains
obstinately silent. Barring all these sources of aberration, however, if
we choose our time wisely, we may succeed in obtaining clear answers,
which persist without interruption.

It is our object, then, to gather the whole history of the plant, during
every moment between its birth and its death. Through how many cycle of
experience it has to pass! The effects on it of recurring light and
darkness; the pull of the earth, and the blow of the storm; how complex
is the concatenation of circumstances, how various are the shocks, and
how multiplex are the replies which we have to analyse! In this vegetal
life which appears so placid and so stationary, how manifold are the
subtle internal reactions! Then how are we to make this invisible
visible?

THE DIARY OF THE PLANT.

The little seedling we know to be growing, but the rate of its growth is
far below anything we can directly perceive. How are we to magnify this
so as to make it instantly measurable? What are the variations in this
infinitesimal growth un