CHAPTER 12.
Reading edition
1843-1846: AGE 36-39.
Completion of Fossil Fishes.—Followed by Fossil Fishes of the Old Red Sandstone.—Review of the Later Work.—Identification of Fishes by the Skull.—Renewed Correspondence with Prince Canino about Journey to the United States.—Change of Plan owing to the Interest of the King of Prussia in the Expedition.—Correspondence between Professor Sedgwick and Agassiz on Development Theory.—Final Scientific Work in Neuchatel and Paris.—Publication of "Systeme Glaciaire."—Short Stay in England.—Farewell Letter from Humboldt. —Sails for United States.