1852-1855: AGE 45-48.
Return to Cambridge.--Anxiety about Collections.--Purchase of
Collections.--Second Winter in Charleston.--Illness.--Letter to
James D. Dana concerning Geographical Distribution and Geological
Succession of Animals.--Resignation of Charleston Professorship.
--Propositions from Zurich.--Letter to Oswald Heer.--Decision to
remain in Cambridge.--Letters to James D. Dana, S.S. Haldeman, and
Others respecting Collections illustrative of the Distribution of
Fishes, Shells, etc., in our Rivers.--Establishment of School for
Girls.