Title: Extracts from letters addressed to Professor Henslow by C. Darwin, Esq. : they are printed for distribution among the members of the Cambridge Philosophical Society, in consequence of the interest which has been excited by some of the geological notices which they contain, and which were read at a meeting of the Society on the 16th of November 1835 ..
Subjects: Natural history, Beagle Expedition (1831-1836)