Something of Agassiz's astonishment and pleasure at the encouragement given to his projected work is told in his letters. To his old friend Professor Valenciennes, in Paris, he writes: "I have just had an evidence of what one may do here in the interest of science. Some six months ago I formed a plan for the publication of my researches in America, and determined to carry it out with all possible care and beauty of finish. I estimated my materials at ten volumes, quarto, and having fixed the price at 60 francs (12 dollars) a volume, thought I might, perhaps, dispose of five hundred. I brought out my prospectus, and I have to-day seventeen hundred subscribers. What do you say to that for a work which is to cost six hundred francs a copy, and of which nothing has as yet appeared? Nor is the list closed yet, for every day I receive new subscriptions,--this very morning one from California! Where will not the love of science find its niche!". . . In the same strain he says, at a little later date, to Sir Charles Lyell: "You will, no doubt, be pleased to learn that the first volume of my new work, 'Contributions to the Natural History of the United States,' which is to consist of ten volumes, quarto, is now printing, to come out this summer. I hope it will show that I have not been idle during ten years' silence. I am somewhat anxious about the reception of my first chapter, headed, 'Classification,' which contains anything but what zoologists would generally expect under that head. The subscription is marvelous. Conceive twenty-one hundred names before the appearance of the first pages of a work costing one hundred and twenty dollars! It places in my hands the means of doing henceforth for Natural History what I had never dreamed of before.". . .