Agassiz writes to his sister Cecile: "I hesitated for a long time to accept this honorable offer, fearing that the occupation might withdraw me too much from my studies; but, on the other hand, the opportunity for laying the foundation of a reputation by a large undertaking seemed too favorable to be refused. The first volume is already finished, and the printing was begun some weeks ago.... Already forty colored folio plates are completed. Will it not seem strange when the largest and finest book in papa's library is one written by his Louis? Will it not be as good as to see his prescription at the apothecary's? It is true that this first effort will bring me in but little; nothing at all, in fact, because M. de Martius has assumed all the expenses, and will, of course, receive the profits. My share will be a few copies of the book, and these I shall give to the friends who have the first claim." He writes to his father, as though half apologizing for the fact that he is writing a book on natural history, at the same time showing the real purpose of his life: "I wish it may be said of Louis Agassiz that he was the first naturalist of his time, a good citizen, and a good son, beloved of those who knew him. I feel within myself the strength of a whole generation to work toward this end, and I will reach it if the means are not wanting." Thus early in life he had fixed the mark to which he would attain, "the first naturalist of his time." No wonder he succeeded, when he felt within himself "the strength of a whole generation to work toward this end." In the summer of 1829, when he was twenty-two, the first part of the "Brazilian Fishes" was published, and a copy sent to the fond parents. Good M. Agassiz wrote back: "I have no terms in which to express the pleasure it has given me. In two words, for I have only a moment to myself, I repeat my urgent entreaty that you would hasten your return as much as possible.... The old father, who waits for you with open heart and arms, sends you the most tender greeting." He had been devoting his time to science--just what they feared,--but how proud they were to have him succeed! Cuvier, the great leader in zoölogy, to whom the book was dedicated, wrote back: "You and M. de Martius have done me honor in placing my name at the head of a work so admirable as the one you have just published. The importance and the rarity of the species therein described, as well as the beauty of the figures, will make the work an important one in ichthyology, and nothing could heighten its value more than the accuracy of your descriptions. It will be of the greatest use to me in my 'History of Fishes.'... I shall do all in my power to accelerate the sale among amateurs, either by showing it to such as meet at my house, or by calling attention to it in scientific journals."