Chapter 12: 1843-1846: Aet. 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. -- sails for United States.
In 1843 the ‘Recherches sur les Poissons Fossiles’ was completed, and fast upon its footsteps, in 1844, followed the author's ‘Monograph on the Fossil Fishes of the Old Red Sandstone, or the Devonian System of Great Britain and Russia,’ a large quarto volume of text, accompanied by forty-one plates. Nothing in his paleontological studies ever interested Agassiz more than this curious fauna of the Old Red, so strange in its combinations that even well-informed naturalists had attributed its fossil remains to various classes of the animal kingdom in turn, and, indeed, long
