. . .Hardly anything in my life has touched me more deeply than the gift I received this week from my school-girls. From no source in the world could sympathy be more genial to me. The money I shall appropriate to a long-cherished scheme of mine, a special work in the Museum which must be exclusively my own,--the arrangement of a special collection illustrating in a nutshell, as it were, all the relations existing among animals,--which I have deferred because other things were more pressing, and our means have been insufficient. The feeling that you are all working with me will be even more cheering than the material help, much needed as that is. I wish I could write to each individually. I shall try to find some means of expressing my thanks more widely. Meantime I write to you as treasurer, and beg you, as far as you can do so without too much trouble, to express my gratitude to others. Will you also say to those whom you chance to meet that I shall be at the Museum on the last Thursday of June, at half-past eleven o'clock. I shall be delighted to see all to whom it is convenient to come. The Museum has grown not only in magnitude, but in scientific significance, and I like from time to time to give you an account of its progress, and of my own work and aims. How much thought and care and effort this kind plan of yours must have involved, scattered as you all are! It cannot have been easy to collect the names and addresses of all those whose signatures it was delightful to me to see again. Words seem to me very poor, but you will accept for yourself and your school-mates the warm thanks and affectionate regards of your old friend and teacher. L.R. AGASSIZ. CHAPTER 18. 1855-1860: AGE 48-53. "Contributions to Natural History of the United States." Remarkable Subscription. Review of the Work. Its Reception in Europe and America. Letters from Humboldt and Owen concerning it. Birthday. Longfellow's Verses. Laboratory at Nahant. Invitation to the Museum of Natural History in Paris. Founding of Museum of Comparative Zoology in Cambridge. Summer Vacation in Europe.