A new and extensive country is the great field for descriptive natural history. The beasts, birds, fishes, reptiles, insects, shells, plants, stones, and rocks are to be examined individually and classed; many new varieties and species are found, and even new genera may occur. The learned Mitchell, of New York, delighted in these branches. The eminent Harlan, of Philadelphia, and McMultrie were of a later and more philosophic school. Nuttall, of Cambridge, has distinguished himself in natural history, and Haldeman is rising to eminence. Ornithology is one of the most attractive branches of natural history. Wilson was the pioneer; Ord, his biographer, followed, and his friend Titian Peale; Audubon is universally known, and stands preëminent; and the learned Nuttall and excellent and enthusiastic Townsend are much respected. Most of these men have compassed sea and land, and encountered many perils and hardships to find their specimens. They have explored the mountains of the North, the swamps of Florida, the prairies of the West, and accompanied the Exploring Expedition to the Antarctic, and round the world. As botanists, the Bartrams, Barton, and Collins, of Philadelphia, Torrey, of New York, Gray and Nuttall of Cambridge, Darlington, of Westchester, are much esteemed. The first botanical garden in our country was that of the Bartons, near Philadelphia; and the first work on botany was from Barton, of the same city. Logan, Woodward, Brailsford, Shelby, Cooper, Horsfield, Colden, Clayton, Muhlenburg, Marshall, Cutler, and Hosack, were also distinguished in this delightful branch. A study of the shells of our country has raised to eminence the names of Barnes, Conrad, Lea, and Raffinesque. The magnificent fresh-water shells of our Western rivers are unrivalled in the Old World in size and beauty. How interesting would be a collection of all the specimens which the organic kingdom of America presents, properly classified and arranged according to the regions and States whence they were brought! Paris has the museum of the natural history of France, and London of Great Britain; but Washington has no museum[5] of the United States, though so much richer in all these specimens.