CHAPTER 17.. 1852-1855: Age 45-48.

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.