It had been a pleasant stroll, I thought,--nothing more; but it proved to be the beginning of an adventure which, to me at least, was in the highest degree novel and interesting. I ought, perhaps, to premise that the solitary vireo (called also the blue-headed vireo and the blue-headed greenlet) is strictly a bird of the woods. It belongs to a distinctively American family, and is one of five species which are more or less abundant as summer residents in Eastern Massachusetts, being itself in most places the least numerous of the five, and, with the possible exception of the white-eye, the most retiring. My own hunting-grounds happen to be one of its favorite resorts (there is none better in the State, I suspect), so that I am pretty certain of having two or three pairs under my eye every season, within a radius of half a mile. I have found a number of nests, also, but till this year had never observed any marked peculiarity of the birds as to timidity or fearlessness. Nor do I now imagine that any such strong race peculiarity exists. What I am to describe I suppose to be nothing more than an accidental and unaccountable idiosyncrasy of the particular bird in question. Such freaks of temperament are more or less familiar to all field naturalists, and may be taken as extreme developments of that individuality which seems to be the birthright of every living creature, no matter how humble. At this very moment I recall a white-throated sparrow, overtaken some years ago in an unfrequented road, whose tameness was entirely unusual, and, indeed, little short of ridiculous.