To William Thompson 18 February [1846?]1
Down Bromley Kent
I am much obliged for your kindness in sending me the note on the Atlantic Dust, as in case I ever get many more facts together, I may perhaps publish an additional note.—
With respect to the migration of Birds, it would be a sincere pleasure to me to aid, even in the smallest degree, one whose writings I have for several years been accustomed to read with much pleasure & instruction; but I really have nothing to say: I apprehend Forbes alluded to a mere speculation of mine (not grounded on facts & therefore quite useless to anyone) that birds probably followed lines of now lost & sunken land. I merely alluded to this notion of mine, when talking with Forbes on his views on the distribution of plants on land since subsided.— In some future year I intend publishing on the variation of plants & animals in the domestic & natural state, & I shall then (I fear) not be able to refrain from some speculations on this & allied subjects, but, as I have said, I really have no facts, or speculations of sufficient importance to be at all worth communicating in detail.— I am sorry that you shd. have had the trouble of writing for nothing; but may I be permitted to hope that our communication on paper may some day lead to our personal acquaintance.
I shall look forward with interest to your work containing your observations: I beg to remain, dear Sir | Your faithfull & obed: sevt. | C. Darwin
Thanks for note on Atlantic dust.
Suggested in private to Edward Forbes that bird migration might follow lines of now sunken land.
Has admired WT’s work for years.
Will some day publish on variation.