On the morrow the party broke up, and Agassiz and Desor, accompanied by their friend, M. Escher de la Linth, returned to the Grimsel, and after a day's rest there repaired once more to the Hotel des Neuchatelois. They remained on the glacier until the 5th of September, spending these few last days in completing their measurements, and in planting the lines of stakes across the glacier, to serve as a means of determining its rate of movement during the year, and the comparative rapidity of that movement at certain fixed points. Thus concluded one of the most eventful seasons Agassiz and his companions had yet passed upon the Alps.* (* Though quoting his exact language only in certain instances, the account of this and other Alpine ascensions described above has been based upon M. E. Desor's "Sejours dans les Glaciers". His very spirited narratives, added to my own recollections of what I had heard from Mr. Agassiz himself on the same subject, have given me my material.--E.C.A.) CHAPTER 11. 1842-1843: AGE 35-36. Zoological Work uninterrupted by Glacial Researches. Various Publications. "Nomenclator Zoologicus." "Bibliographia Zoologiae et Geologiae." Correspondence with English Naturalists. Correspondence with Humboldt. Glacial Campaign of 1842. Correspondence with Prince de Canino concerning Journey to United States. Fossil Fishes from the Old Red Sandstone. Glacial Campaign of 1843. Death of Leuthold, the Guide. Although his glacier work was now so prominent a feature of Agassiz's scientific life, his zoological studies, especially his ichthyological researches, and more especially his work on fossil fishes, went on with little interruption. His publications upon Fossil Mollusks,* (* "Etudes Critiques sur les Mollusques Fossiles" 4 numbers quarto with 100 plates.) upon Tertiary Shells,* (* "Iconographie des Coquilles Tertiaires reputees identiques sur les vivans" 1 number quarto 14 plates.) upon Living and Fossil Echinoderms,* (* "Monographie d'Echinodermes vivans et fossiles" 4 numbers quarto with 37 plates.) with many smaller monographs on special subjects, were undertaken and completed during the most active period of his glacial investigations. More surprising is it to find him, while pursuing new lines of investigation with passionate enthusiasm, engaged at the same time upon works seemingly so dry and tedious as his "Nomenclator Zoologicus," and his "Bibliographia Zoologiae et Geologiae." The former work, a large quarto volume with an Index,* (* The Index was also published separately as an octavo.) comprised an enumeration of all the genera of the animal kingdom, with the etymology of their names, the names of those who had first proposed them, and the date of their publication. He obtained the cooperation of other naturalists, submitting each class as far as possible for revision to the leaders in their respective departments.