IN THE thick woods of chestnut and oak at the foot of Slanting Pasture, wood thrushes, rose-breasted grosbeaks and blue headed vireos were singing, each heedless of all the rest. Abruptly their music lulled. A low humming sound, which seemed to come from all directions at once, filled the air. Low as the sound was, thrush, grosbeak and vireo fell silent. A sudden stillness hung over the high upland pasture, sparkling with dew and starred with innumerable daisies—a hush heavy with expectation, laden with peril.
Possibly some finer sense than that of hearing had warmed the singing birds along the forest's edge. Not until the bird chorus had lulled did the bearded, blue-shirted mountaineer, hidden in a coppice of alder near the middle of the pasture, detect that vibrant hum. At the same moment a bunch of twenty sheep grazing fifty yards to the right of the coppice caught the sound and huddled. One of their number left the flock, ran forward a few paces, then stopped, staring stupidly.
In the brief interval which had elapsed the hum ming sound had sharpened to a hiss. A great dark
