WHEN one knows six birds by sight or sound, it has been said, he is lost. After that he cannot rest until he knows fifty, or a hundred, or two hundred--in his back-door yard, or down in the orchard, or across the farm. It is not easy to explain wherein lies the fascination of "naming the birds without a gun." The humility of the scoffer, caught unawares, and taught his first six before he knows it, is something pathetic and instructive. Few mortals are proof against the charm--when once the first half-dozen are conquered. The first three come easy. Most of us know the Crow--and the Robin--and the Bluebird--and--and--the Sparrow--until we discover that there are more than a dozen varieties of Sparrow, and perceive that this common brown bird, hopping so cheerily in and out of the bushes, may be a Song Sparrow or a Chipping Sparrow or a White-Throated or White-Crowned or any one of the dozen--or even the Cocky English Sparrow, despised by ornithologist and tyro alike. When to the Crow and Robin and Bluebird one has added the Blackbird--both the Keel-tailed and the Redwing--and the Meadow Lark or the Highhole, the charm begins to work. Armed with opera-glass and bird book, the victim casts convention to the winds. He stands in the full glare of the public highway, his glass focused on an invisible spot, an object of ridicule to men and dogs. He crawls on his hands and knees through underbrush, under barbed fences and over stone walls. He sits by the hour waiting for a Vireo to come down from the topmost branch within range of his glass. He forgets luncheon and engagements. And what does he bring home? Certainly not the river and sky, and seldom even a feather. Books on birds, continues the _Boston Evening Transcript_, like good wine, need no bush at this season of the year; the Golden-winged Woodpecker drums announcement on every limb; the Redwing Blackbird gurgles and chuckles and calls across the swamp; and the Lesser Sparrows and Bluebirds and Robins wake the morning to the weaving of new song. The hand reaches out for the familiar bird-book; that last note was a strange one. It is a new bird--or merely one forgotten? The delight begins all over with the first Bluebird's call, "a mere wandering voice in the air."