But, if such be the rule, there are at least some glaring exceptions. I have alluded to the rude structure of the rose-breast, and might have used nearly the same language concerning the tanager's, which latter is often fabricated so loosely that one can see the sky through it. Yet these two are among the most gorgeously attired of all our birds. On the other hand, while the wood pewee is one of the very plainest, there are few, if any, that excel her as an architect. During the season under review I had the good fortune to light upon my first nest of this fly-catcher; and, as is apt to be true, having found one, I immediately and without effort found two others. The first two were in oaks, the third in a hornbeam; and all were set upon the upper side of a horizontal bough ("saddled" upon it, as the manuals say), at the junction of an offshoot with the main branch. Two of them were but partially done when discovered, and I was glad to see one pair of the birds in something very like a frolic, such a state as would hardly be predicted of these peculiarly sober-seeming creatures. The builder of the second nest was remarkably confiding, and proceeded with her labors, quite undisturbed by my proximity and undisguised interest. It was to be remarked that she had trimmed the outside of her nest with lichens before finishing the interior; and I especially admired the very clever manner in which she hovered against the dead pine-trunk, from which she was gathering strips of bark. Concerning her unsuspiciousness, however, it should be said that the word applies only to her treatment of myself. When a thrasher had the impertinence to alight in her oak she ordered him off in high dudgeon, dashing back and forth above him, and snapping spitefully as she passed. She knew her rights, and, knowing, dared maintain. When a bird builds her nest in any part of a tree she claims every twig of it as her own. I have even seen the gentle-hearted chickadee resent the intrusion of a chipping sparrow, though it appeared impossible that the latter could be suspected of any predatory or sinister design. The shallowness of the wood pewee's saucer-shaped nest, its position upon the branch, and especially its external dress of lichens, all conspire to render it inconspicuous. It is an interesting question whether the owner herself appreciates this, or has merely inherited the fashion, without thought of the reasons for it. The latter supposition, I reluctantly confess, looks to me the more probable. It must often be true of other animals, as it is of men, that they build better than they know. Their wisdom is not their own, but belongs to a power back of them,--a power which works, if you will, in accordance with what we designate as the law of natural selection, and which, so to speak, enlightens the race rather than the individual.