Dear Sir

I thank you very sincerely for communicating to me your discovery, & it is a most interesting one—¹ It is especially important at the present time when several naturalists have declared that development occurs quite suddenly at intervals— Thus M^r Le Conte in N. America urges that even new families or orders are developed within an extremely short period:² Whenever I read such views I think of your observations on the Tertiary European Flora, and on those of D^r. Neumayr on the Freshwater Shells in the Congerian beds, & then I return to my old faith that such views are erroneous—³ I saw lately in a journal that you have discovered a true fern in a Silurian formation⁴   If my dear old friend Lyell had been alive how he would have rejoiced over these two great steps in the history of the vegetable kingdom—⁵

With cordial good wishes, & a firm belief that you will make many more important discoveries— | I remain Dear Sir. | Yours faithfully— | Charles Darwin.