From A. R. Wallace   21 July 1875

Dear Darwin

Many thanks for your kindness in sending me a copy of your new book.¹ Being very busy I have only had time to dip into it yet. The account of Utricularia is most marvellous & quite new to me. I am rather surprised that you do not make any remarks on the origin of these extraordinary contrivances for capturing insects.² Did you think they were too obvious? I dare say there is no difficulty, but I feel sure they will be seized on as inexplicable by Nat. Select. & your silence on the point will be held to show that you consider them so! The contrivance in Utricularia & Dionæa, & in fact in Drosera too, seems fully as great & complex as in Orchids, but there is not the same motive force.³ Fertilization & cross fertilization are important ends enough to lead to any modification,—but can we suppose mere nourishment to be so important, seeing that it is so easily & almost universally obtained by extension of roots & leaves. Here are plants which lose their roots & leaves to acquire the same results by infinitely complex modes! What a wonderfull & long continued series of variations must have led up to the perfect “trap” in Utricularia, while at any stage of the process the same end might have been gained by a little more development of roots & leaves, as in 9999 plants out of 10,000!

Is this an imaginary difficulty or do you mean to deal with it in future editions of the “Origin”?⁴

Believe me | Yours very faithfully| Alfred R. Wallace