Is obliged to receive FH's papers. The cases of Lopezia and Schizanthus are new to him.
In 1860 CD watched Bombus lapidarius sucking the flowers of Pedicularis sylvestris and saw what FH has described.
Has not yet read the paper on Salvia.
Down. | Bromley. | Kent. S.E.
I am very much obliged to you for so kindly sending me your most interesting
papers. The cases of Lopezia & Schizanthus are quite new
to me. A Botanical friend, M
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.—
Several years ago I protected Medicago lupulina from insects, & its fertility was much impaired, but not wholly prevented. 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.—
I hope that you will continue your interesting researches, & with sincere respect, | remain Dear Sir | Yours truly obliged | Ch. Darwin
- f1 5062a.f1CD had received copies of Hildebrand 1866a and 1866b. See letter to George Henslow, 16 April  and nn. 2 and 5.
- f2 5062a.f2For Hildebrand's descriptions of Lopezia coronata and Schizanthus pinnatus, see Hildebrand 1866a, pp. 75--7.
- f3 5062a.f3George Henslow had visited CD from 2 to 3 or 4 April 1866 (Emma Darwin's diary (DAR 242)). He had been preparing a paper on pollination mechanisms in Indigofera (see letter to George Henslow, 16 April  and n. 2).
- f4 5062a.f4Pedicularis sylvatica, commonly known as lousewort, is described in Hildebrand 1866a, pp. 10--11. CD reported his observations of bees visiting P. sylvatica in Cross and self fertilisation, p. 422.
- f5 5062a.f5CD had written a note on Medicago lupulina that was included in a paper by Henslow on cross-pollination by insects in Medicago sativa (Henslow 1865). See Correspondence vol. 13, letter to George Henslow, [2--5 November 1865]. CD's observations were also published in Cross and self fertilisation, p. 368. His notes on M. lupulina, dated 1859, are in DAR 157a: 45.
- f6 5062a.f6CD refers to Hildebrand 1866b. See letter to George Henslow, 16 April  and n. 5.