My dear Darwin

Many thanks for your new book containing your wonderful series of experiments & observations on the movements of plants.¹ I have read the introduction and conclusion, which shows me the importance of the research as indicating the common basis of the infinitely varied habits and mode of growth of plants. The whole subject becomes thus much simplified, though the nature of the basic vitality which leads to such wonderful results remains as mysterious as ever.

Yours very faithfully | Alfred R. Wallace

Charles Darwin F. R. S.