In the above letter to his brother we have the story of his work during the whole winter of 1830. That his medical studies did not suffer from the fact that, in conjunction with them, he was carrying on his two great works on the living and the dead world of fishes may be inferred from the following account of his medical theses. It was written after his death, to his son Alexander Agassiz, by Professor von Siebold, now Director of the Museum in the University of Munich. "How earnestly Agassiz devoted himself to the study of medicine is shown by the theses (seventy-four in number), a list of which was printed, according to the prescribed rule and custom, with his 'Einladung.' I am astonished at the great number of these. The subjects are anatomical, pathological, surgical, obstetrical; they are inquiries into materia medica, medicina forensis, and the relation of botany to these topics. One of them interested me especially. It read as follows. 'Foemina humana superior mare.' I would gladly have known how your father interpreted that sentence. Last fall (1873) I wrote him a letter, the last I ever addressed to him, questioning him about this very subject. That letter, alas! remained unanswered." In a letter to his brother just before taking his degree, Agassiz says: "I am now determined to pursue medicine and natural history side by side. Thank you, with all my heart, for your disinterested offer, but I shall not need it, for I am going on well with my publisher, M. Cotta, of Stuttgart. I have great hope that he will accept my works, since he has desired that they should be forwarded to him for examination. I have sent him the whole, and I feel very sure he will swallow the pill. My conditions would be the only cause of delay, but I hope he will agree to them. For the fresh-water fishes and the fossils together I have asked twenty thousand Swiss francs. Should he not consent to this, I shall apply to another publisher." On the 3rd of April he received his degree of Doctor of Medicine. A day or two later he writes to his mother that her great desire for him is accomplished. TO HIS MOTHER. MUNICH, April, 1830.