It was not long before his growing reputation brought him invitations from elsewhere. One of the first of these was from Heidelberg.

PROFESSOR TIEDEMANN TO LOUIS AGASSIZ.

HEIDELBERG, December 4, 1832.

. . .Last autumn, when I had the pleasure of meeting you in Carlsruhe, I proposed to you to give some lectures on Natural History at this university. Professor Leuckart, who till now represented zoology here, is called to Freiburg, and you would therefore be the only teacher in that department. The university being so frequented, a numerous audience may be counted upon. The zoological collection, by no means an insignificant one, is open to your use. Professor Leuckart received a salary of five hundred florins. This is now unappropriated, and I do not doubt that the government, conformably to the proposition of the medical faculty, would give you the appointment on the same terms. By your knowledge you are prepared for the work of an able academical teacher. My advice is, therefore, that you should not bind yourself to any lyceum or gymnasium, as a permanent position; such a place would not suit a cultivated scientific man, nor does it offer a field for an accomplished scholar. Consider carefully, therefore, a question which concerns the efficiency of your life, and give me the result of your deliberation as soon as possible. Should it be favorable to the acceptance of my proposition, I hope you will find yourself here at Easter as full professor, with a salary of five hundred florins, and a fitting field of activity for your knowledge. The fees for lectures and literary work might bring you in an additional fifteen hundred gulden yearly. If you accede to this offer send me your inaugural dissertation, and make me acquainted with your literary work, that I may take the necessary steps with the Curatorio. Consider this proposition as a proof of my high appreciation of your literary efforts and of my regard for you personally.

Agassiz's next letter to Humboldt is to consult him with respect to the call from Heidelberg, while it is also full of pleasure at the warm welcome extended to him in Neuchatel.

AGASSIZ TO HUMBOLDT.

December, 1832.

. . .At last I am in Neuchatel, having, indeed, begun my lectures some weeks ago. I have been received in a way I could never have anticipated, and which can only be due to your good-will on my behalf and your friendly recommendation. You have my warmest thanks for the trouble you have taken about me, and for your continued sympathy. Let me show you by my work in the years to come, rather than by words, that I am in earnest about science, and that my spirit is not irresponsive to a noble encouragement such as you have given me.

You will have received my letter from Carlsruhe. Could I only tell you all that I have since thought and observed about the history of our earth's development, the succession of the animal populations, and their genetic classification! It cannot easily be compressed within letter limits; I will, nevertheless, attempt it when my lectures make less urgent claim upon me, and my eyes are less fatigued. I should defer writing till then were it not that to-day I have something of at least outside interest to announce. It concerns the inclosed letter received to-day. (The offer of a professorship at Heidelberg.) Should you think that I need not take it into consideration, and you have no time to answer me, let me know your opinion by your silence. I will tell you the reasons which would induce me to remain for the present in Neuchatel, and I think you will approve them. First, as my lectures do not claim a great part of my time I shall have the more to bestow on other work; add to this the position of Neuchatel, so favorable for observations such as I propose making on the history of development in several classes of animals; then the hope of freeing myself from the burden of my collections; and next, the quiet of my life here with reference to my somewhat overstrained health. Beside my wish to remain, these favorable circumstances furnish a powerful motive, and then I am satisfied that people here would assist me with the greatest readiness should my publications not succeed otherwise. As to the publication of my fishes, I can, after all, better direct the lithographing of the plates here. I have just written to Cotta concerning this, proposing also that he should advance the cost of the lithographs. I shall attend to it all carefully, and be content for the present with my small means. From the gradual sale he can, little by little, repay my expenses, and I shall ask no profit until the success of the work warrants it. I await his answer. This proposal seems to me the best and the most likely to advance the publication of this work.

Since I arrived here some scientific efforts have been made with the help of M. Coulon. We have already founded a society of Natural History,* (* Societe des Sciences Naturelles de Neuchatel.) and I hope, should you make your promised visit next year, you will find this germ between foliage and flower at least, though perhaps not yet ripened into seed. . .