And now I bring this book to a conclusion.  So many things requiring attention have happened since it was begun that I leave it in a very different shape to the one which it was originally intended to bear.  I have omitted much that I had meant to deal with, and have been tempted sometimes to introduce matter the connection of which with my subject is not immediately apparent.  Such however, as the book is, it must now go in the form into which it has grown almost more in spite of me than from malice prepense on my part.  I was afraid that it might thus set me at defiance, and in an early chapter expressed a doubt whether I should find it redound greatly to my advantage with men of science; in this concluding chapter I may say that doubt has deepened into something like certainty.  I regret this, but cannot help it.

Among the points with which it was most incumbent upon me to deal was that of vegetable intelligence.  A reader may well say that unless I give plants much the same sense of pleasure and pain, memory, power of will, and intelligent perception of the best way in which to employ their opportunities that I give to low animals, my argument falls to the ground.  If I declare organic modification to be mainly due to function, and hence in the closest correlation with mental change, I must give plants, as well as animals, a mind, and endow them with power to reflect and reason upon all that most concerns them.  Many who will feel little difficulty about admitting that animal modification is upon the whole mainly due to the secular cunning of the animals themselves will yet hesitate before they admit that plants also can have a reason and cunning of their own.

Unwillingness to concede this is based principally upon the error concerning intelligence to which I have already referred—­I mean to our regarding intelligence not so much as the power of understanding as that of being understood by ourselves.  Once admit that the evidence in favour of a plant’s knowing its own business depends more on the efficiency with which that business is conducted than either on our power of understanding how it can be conducted, or on any signs on the plant’s part of a capacity for understanding things that do not concern it, and there will be no further difficulty about supposing that in its own sphere a plant is just as intelligent as an animal, and keeps a sharp look-out upon its own interests, however indifferent it may seem to be to ours.  So strong has been the set of recent opinion in this direction that with botanists the foregoing now almost goes without saying, though few five years ago would have accepted it.