Note 20 — WINTER BIRDS ABOUT BOSTON.

See a letter by Dr. Fritz Müller, "Butterflies as Botanists:" Nature, vol. xxx. p. 240. Of similar import is the case, cited by Dr. Asa Gray (in the American Journal of Science, November, 1884, p. 325), of two species of plantain found in this country, which students have only of late discriminated, although it turns out that the cows have all along known them apart, eating one and declining the other,—the bovine taste being more exact, it would seem, or at any rate more prompt, than the botanist's lens.