First Important Work in Natural History. Spix's Brazilian Fishes. Second Vacation Trip. Sketch of Work during University Year. Extracts from the Journal of Mr. Dinkel. Home Letters. Hope of joining Humboldt's Asiatic Expedition. Diploma of Philosophy. Completion of First Part of the Spix Fishes. Letter concerning it from Cuvier. It was not without a definite purpose that Agassiz had written to his father some weeks before, "Should I during the course of my studies succeed in making myself known by a distinguished work, would you not then consent that I should study for one year the natural sciences alone?" Unknown to his parents, for whom he hoped to prepare a delightful surprise, Agassiz had actually been engaged for months on the first work which gave him distinction in the scientific world; namely, a description of the Brazilian fishes brought home by Martius and Spix from their celebrated journey in Brazil. This was the secret to which allusion is made in the next letter. To his disappointment an accident brought his undertaking to the knowledge of his father and mother before it was completed. He always had a boyish regret that his little plot had been betrayed before the moment for the denouement arrived. The book was written in Latin and dedicated to Cuvier.* (* "Selecta genera et species piscium quos collegit et pingendos curavit Dr. J.W. de Spix". Digessit, descripsit et observationibus illustravit Dr. L. Agassiz.) TO HIS BROTHER. MUNICH, July 27, 1828. . . .Various things which I have begun keep me a prisoner here. Probably I shall not stir during the vacation, and shall even give up the little trip in the Tyrol, which I had thought of making as a rest from occupations that bind me very closely at present, but from which I hope to free myself in the course of the holidays. Don't be angry with me for not telling you at once what they are. When you know, I hope to be forgiven for keeping you so long in the dark. I have kept it a secret from papa too, though in his last letter he asks me what is my especial work just now. A few months more of patience, and I will give you a strict account of my time since I came here, and then I am sure you will be satisfied with me. I only wish to guard against one thing: do not take it into your head that I am about to don the fool's cap suddenly and surprise you with a Doctor's degree; that would be going a little too fast, nor do I think of it yet. . .I want to remind you not to let the summer pass without getting me fishes according to the list in my last letter, which I hope you have not mislaid. You would give me great pleasure by sending them as soon as possible. Let me tell you why. M. Cuvier has announced the publication of a complete work on all the known fishes, and in the prospectus he calls on such naturalists as occupy themselves with ichthyology to send him the fishes of the country where they live; he mentions those who