Although so deeply interested by the geological features of the country, Agassiz was nevertheless drawn even more strongly to the study of the marine animals for which his position on the sea-coast gave him such opportunities as he had never before had. The next letter shows how fully his time was occupied, and how fascinating this new field of observation was to him. The English is still a little foreign. He was not yet quite at home in the language which he afterward wrote and spoke with such fluency. TO JAMES D. DANA. EAST BOSTON, September, 1847. . . .What have you thought of me all this time, not having written a single line neither to you nor to Professor Silliman after the kind reception I have met with by your whole family? Pray excuse me and consider, if you please, the difficulty under which I labor, having every day to look after hundreds of new things which always carry me beyond usual hours of working, when I am then so much tired that I can think of nothing. Nevertheless, it is a delightful life to be allowed to examine in a fresh state so many things of which I had but an imperfect knowledge from books. The Boston market supplies me with more than I can examine. Since I had the pleasure of seeing you I have been very successful in collecting specimens, especially in New York and Albany. In Washington I have been delighted to see the collections of the Exploring Expedition. They entitle you to the highest thanks from all scientific naturalists, and I hope it will be also felt in the same manner by your countrymen at large. . .I long for the opportunity of studying your fossil shells. As soon as I have gone over my Lowell lectures I hope to be able to move. I shall only pack up what I have already collected; but I cannot yet tell you precisely the time. I began studying your "Zoophytes," but it is so rich a book that I proceed slowly. For years I have not learned so much from a book as from yours. As I soon saw I would not be able to go through in a short time, I sent a short preliminary report to one of our most widely diffused papers, "Preussische Staats Zeitung," giving only the general impression of your work, and I shall send to Erichson a fuller scientific report after I have done with the whole volume. As I happen to have a lithograph of the original specimen of the Homo deluvii testis of Scheuchzer, I will forward it to Professor Silliman with this letter. I expect you will find it the counterpart of the specimen in your museum; or very nearly in the same state of preservation. Having just lately received my books, I also inclose a pamphlet from Ehrenberg, which he desired me to leave with you, and also the books Professor Silliman has had the kindness to lend me. . . I have made many observations which I wish to publish, but I can find no time to write them for you now. I must wait till the weather is so dull as to bring nothing into the hands of gunners and fishermen. . .