obliquity of the point of view. It would, therefore, have been a much
better plan to have used hemispherical glasses, if we had possessed them of
all sizes, and if the bending part of the shoot had been distinctly hinged
and could have been placed so as to have formed one of the radii of the
sphere. But even in this case it would have been necessary afterwards to
have projected the figures on paper; so that complete accuracy could not
have been attained. From the distortion of our figures, owing to the above
causes, they are of no use to any one who wishes to know the exact amount
of movement, or the exact course pursued; but they serve excellently for
ascertaining whether or not the part moved at all, as well as the general
character of the movement.]

In the following chapters, the movements of a considerable number of plants
are described; and the species have been arranged according to the system
adopted by Hooker in Le Maout and Decaisne's 'Descriptive Botany.' No one
who is not investigating the present subject need read all the details,
which, however, we have thought it advisable to give. To save the reader
trouble, the conclusions and most of the more important parts have been
printed in larger type than the other parts. He may, if he thinks fit, read
the last chapter first, as it includes a summary of the whole volume; and
he will thus see what points interest him, and on which he requires the
full evidence.

Finally, we must have the pleasure of returning our
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sincere thanks to Sir Joseph Hooker and to Mr. W. Thiselton Dyer for their
great kindness, in not only sending us plants from Kew, but in procuring
others from several sources when they were required for our observations;
also, for naming many species, and giving us information on various points.
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