The ability, so eminently possessed by Agassiz of dealing with a number of subjects at once, was due to no superficial versatility. To him his work had but one meaning. It was never disconnected in his thought, and therefore he turned from his glaciers to his fossils, and from the fossil to the living world, with the feeling that he was always dealing with kindred problems, bound together by the same laws. Nowhere is this better seen than in the records of the scientific society of Neuchatel, the society he helped to found in the first months of his professorship, and to which he always remained strongly attached, being a constant attendant at its sessions from 1833 to 1846. Here we find him from month to month, with philosophic breadth of thought, treating of animals in their widest relations, or describing minute structural details with the skill of a specialist. He presents organized beings in their geological succession, in their geographical distribution, in their embryonic development. He reviews and remodels laws of classification. Sometimes he illustrates the fossil by the living world, sometimes he finds the key to present phenomena in the remote past. He reconstructs the history of the glacial period, and points to its final chapter in the nearest Alpine valleys, connecting these facts again with like phenomena in distant parts of the globe. But however wide his range and however various his topics, under his touch they are all akin, all coordinate parts of a whole which he strives to understand in its entirety. A few extracts from his correspondence will show him in his different lines of research at this time. The following letter is from Edward Forbes, one of the earliest explorers of the deep-sea fauna. Agassiz had asked him for some help in his work upon echinoderms. EDWARD FORBES TO LOUIS AGASSIZ. 21 LOTHIAN ST., EDINBURGH, February 13, 1841.