. . .I hope when you read this letter you will have received the first part of my Brazilian Fishes from M.--, of Geneva, to whom Martius had to send a package of plants, with which my book was inclosed. I venture to think that this work will give me a name, and I await with impatience the criticism that I suppose it will receive from Cuvier. . .I think the best way of reaching the various aims I have in view is to continue the career on which I have started, and to publish as soon as possible my natural history of the fresh-water fishes of Germany and Switzerland. I propose to issue it in numbers, each containing twelve colored plates accompanied by six sheets of letter-press. . .In the middle of September there is to be a meeting of all the naturalists and medical men of Germany, to which foreign savants are invited. A similar meeting has been held for the last two or three years in one or another of the brilliant centres of Germany. This year it will take place at Heidelberg. Could one desire a better occasion to make known a projected work? I could even show the original drawings already made of species only found in the environs of Munich, and, so to speak, unknown to naturalists. At Heidelberg will be assembled Englishmen, Danes, Swedes, Russians, and even Italians. If I could before then arrange everything and distribute the printed circulars of my work I should be sure of success. . . In those days of costly postage one sheet of writing paper was sometimes made to serve for several members of the family. The next crowded letter contains chiefly domestic details, but closes with a postscript from Mme. Agassiz, filling, as she says, the only remaining corner, and expressing her delight in his diploma and in the completion of his book. FROM HIS MOTHER. August 16, 1829. . . .The place your brother has left me seems very insufficient for all that I have to say, dear Louis, but I will begin by thanking you for the happiness, as sweet as it is deeply felt, which your success has given us. Already our satisfaction becomes the reward of your efforts. We wait with impatience for the moment when we shall see you and talk with you. Your correspondence leaves many blanks, and we are sometimes quite ashamed that we have so few details to give about your book. You will be surprised that it has not yet reached us. Does the gentleman in Geneva intend to read it before sending it to us, or has he perhaps not received the package? Not hearing we are uneasy. . .Good-by, my dear son; I have no room for more, except to add my tender love for you. An honorable mention of your name in the Lausanne Gazette has brought us many pleasant congratulations. . . TO HIS FATHER. August, 1829.