The result of this expedition was a valuable collection of fishes and a report upon the fauna and the geology of Lake Superior, comprising the erratic phenomena. A narrative written by James Elliot Cabot formed the introduction to the report, and it was also accompanied by two or three shorter contributions on special subjects from other members of the party. The volume was illustrated by a number of plates exquisitely drawn and colored on stone by A. Sonrel. This was not Agassiz's first publication in America. His "Principles of Zoology" (Agassiz and Gould) was published in 1848. The book had a large sale, especially for schools. Edition followed edition, but the sale of the first part was checked by the want of the second, which was never printed. Agassiz was always swept along so rapidly by the current of his own activity that he was sometimes forced to leave behind him unfinished work. Before the time came for the completion of the second part of the zoology, his own knowledge had matured so much, that to be true to the facts, he must have remodeled the whole of the first part, and for this he never found the time. Apropos of these publications the following letters are in place. FROM SIR RODERICK MURCHISON. BELGRAVE SQUARE, October 3, 1849. . . .I thank you very sincerely for your most captivating general work on the "Principles of Zoology." I am quite in love with it. I was glad to find that you had arranged the nummulites with the tertiary rocks, so that the broad generalization I attempted in my last work on the Alps, Apennines, and Carpathians is completely sustained zoologically, and you will not be sorry to see the stratigraphical truth vindicated (versus E. de Beaumont and--). I beseech you to look at my memoir, and especially at my reasoning about the miocene and pliocene divisions of the Alps and Italy. It seems to me manifest that the percentage system derived from marine life can never be applied to tertiary TERRESTRIAL successions. . . My friends have congratulated me much on this my last effort, and as Lyell and others most interested in opposing me have been forward in approval, I begin to hope that I am not yet quite done up; and that unlike the Bishop of Oviedo, my last sermon "ne sent pas de l'apoplexie." I have, nevertheless, been desperately out of sorts and full of gout and liver and all kinds of irritation this summer, which is the first for many a long year in which I have been unable to take the field. The meeting at Birmingham, however, revived me. Professor W. Rogers will have told you all about our doings. Buckland is up to his neck in "sewage," and wishes to change all underground London into a fossil cloaca of pseudo coprolites. This does not quite suit the chemists charged with sanitary responsibilities; for they fear the Dean will poison half the population in preparing his choice manures! But in this as in everything he undertakes there is a grand sweeping view.