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262 seem very foreign to this locality,—no nearer than Hudson's Bay,—and for some weeks or months I go thinking of it, and expecting it, unconsciously, and at length I surely see it. This is the history of my finding a score or more of rare plants, which I could name. A man sees only what concerns him. . A botanist absorbed in the study of grasses does not distinguish the grandest Pasture Oaks. He, as it were, tramples down Oaks unwittingly in his walk, or at most sees only their shadows. I have found that it required a different intention of the eye, in the same locality, to see different plants, even when they were closely allied, as Juncaceæ and Gramineæ: when I was looking for the former, I did not see the latter in the midst of them. How much more, then, it requires different intentions of the eye and of the mind to attend to different departments of knowledge! How differently the poet and the naturalist look at objects!

Take a New-England selectman, and set him on the highest of our hills, and tell him to look,—sharpening his sight to the utmost, and putting on the glasses that suit him best, (ay, using a spy-glass, if he likes,)—and make a full report. What, probably, will he spy?—what will he select to look at? Of course, he will see a Brocken spectre of himself. He will see