From J. S. Henslow   5 May 1860

My dear Darwin,

I read your wishes to my Class—& yesterday after lecture a few of us walked to Cherry Hinton—¹ I found the Elodea had made great progress since I saw it a year or two ago—   It is now quite up to the source of th⁠⟨⁠e⁠⟩⁠ stream & fills the ditches, in Cherry Hinton itself— But I find this stream is not connected with the water course that runs past the Botanic Garden (as I had supposed) but runs down to the paper mills beyond Barnwell—   It seems therefore to have travelled up from the river itself which is full of it—   So far as mere recollection guides me it seems to have greatly diminished the quantity of Ranunculus aquatilis var fluitans which used to abound in the stream at the part we visited— It decidedly preponderates over every other aquatic, but I found it associated with Potamogeton densus (in small quantity) & Ranunculus aquatilis, & intermixed with plants of the Lemna trisulca—

Sedgwick is to illuminate us on Monday at the Philosophical Society in regard to your supposed errors!² How can Owen be so savage with your views when his own are to a certain extent of the same character—³ If I understand him, he thinks the “Becoming” of species (I suppose he means the producing of species), a somewhat rapid & not a slow process—but he seems to think them progressive organised out of previously organized beings—

analogous (?) to minerals (simple & compound) out of some + - 60 Elements

   I don’t think it is at all becoming in one Naturalist to be bitter against another—any more than for one sect to burn the members of another—

Kind regards to M^rs D.— &c— Y^rs affect^ly | J S Henslow