2nd. You will not have forgotten either that you exacted this only that I might have a profession, and that you promised, should I be able to make my way in the career of letters and natural history, you would not oppose my wishes. I am indeed aware that in the latter case you see but one obstacle, that of absence from my country and separation from all who are dear to me. But you know me too well to think that I would voluntarily impose upon myself such an exile. Let us see whether we cannot resolve these difficulties to our mutual satisfaction, and consider what is the surest road to the end I have proposed to myself ever since I began my medical studies. Weigh all my reasons, for in this my peace of mind and my future happiness are concerned. Examine my conduct with reference to what I propose in every light, that of son and Vaudois citizen included, and I feel sure you will concur in my views. Here is my aim and the means by which I propose to carry it out. 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. Let us see in what these means consist. [Here follows the summing up of his reasons for preferring a professorship of natural history to the practice of medicine, and his intention of trying for a diploma as Doctor of Philosophy in Germany.] But how obtain a professorship, you will say,--that is the important point? I answer, the first step is to make myself a European name, and for that I am on the right road. In the first place my work on the fishes of Brazil, just about to appear, will make me favorably known. I am sure it will be kindly received; for at the General Assembly of German naturalists and medical men last September, in Berlin, the part already finished and presented before the Assembly was praised in a manner for which I was quite unprepared. The professors also, to whom I was known, spoke of me there in very favorable terms.