The botanical professor, the genial Von Martius, should also be mentioned here. He found Agassiz a student, barely of age; he directly made him an author, and an authority, in the subject of his predilection. Dr. Spix, the zooelogical companion of Martius in Brazilian exploration, died in 1826; the fishes of the collection were left untouched. Martius recognized the genius of Agassiz, and offered him, and indeed pressed him, to undertake their elaboration. Agassiz brought out the first part of the quarto volume on the "Fishes of the Brazilian Expedition of Spix and Martius" before he took his degree of doctor of philosophy, and completed it before he proceeded to that of doctor in medicine, in 1830. The work opened his way to fame, but brought no money. Still, as Martius defrayed all the expenses, the net result compared quite favorably with that of later publications. Moreover, out of it possibly issued his own voyage to Brazil in later years, under auspices such as his early patron never dreamed of. This early work also made him known to Cuvier; so that, when he went to Paris, a year afterward, to continue his medical and scientific studies--the one, as he deemed, from necessity, the other from choice--he was received as a fellow-savant; yet at first with a certain reserve, probably no more than was natural in view of the relative age and position of the two men; but Agassiz, writing to his sister, says: "This extreme but formal politeness chills you instead of putting you at your ease; it lacks cordiality, and, to tell the truth, I would gladly go away if I were not held fast by the wealth of material of which I can avail myself." But only a month later he writes--this time to his uncle--that, while he was anxious lest he "might not be allowed to examine, and still less to describe, the fossil fishes and their skeletons in the Museum, ... knowing that Cuvier intended to write a work on this subject," and might naturally wish to reserve the materials for his own use; and when the young naturalist, as he showed his own sketches and notes to the veteran, was faintly venturing to hope that, on seeing his work so far advanced, he might perhaps be invited to share in a joint publication, Cuvier relieved his anxiety and more than fulfilled his half-formed desires. "He desired his secretary to bring him a certain portfolio of drawings. He showed me the contents: they were drawings of fossil fishes, and notes which he had taken in the British Museum and elsewhere. After looking it through with me, he said he had seen with satisfaction the manner in which I had treated this subject; that I had, indeed, anticipated him, since he had intended at some future time to do the same thing; but that as I had given it so much attention, and had done my work so well, he had decided to renounce his project, and to place at my disposition all the materials he had collected and all the preliminary notes he had taken."