Dear Sir

I am very much obliged to you for so kindly sending me your most interesting papers.¹ The cases of Lopezia & Schizanthus are quite new to me.² A Botanical friend, M^r. Henslow, was staying here a fortnight since, & detected & showed to me the curious movements in Indigofera, which grew in my greenhouse.—³

You may perhaps like to hear that in 1860 I watched Bombus lapidarius sucking the flowers of Pedicularis sylvatica, & I saw all that you describe: when the Bee forced its head into the corolla, the slit in the upper helmet-like petal opened & the anthers & stigma were rubbed on its back, so that its back was white with pollen.—⁴

Several years ago I protected Medicago lupulina from insects, & its fertility was much impaired, but not wholly prevented.⁵ I know of many cases in which in the same genus one species requires insect aid & another is sufficiently or fully fertile without such aid; but in this latter case the flowers are nevertheless repeatedly crossed by adjoining plants.

I have not yet read your paper on Salvia, but I recognize the beautiful structures in your excellent drawings with which I am familiar.—⁶

I hope that you will continue your interesting researches, & with sincere respect, | remain Dear Sir | Yours truly obliged | Ch. Darwin