he birds had all the while been singing close about him, but in every instance had passed for "nothing but red-eyes."
 Bulletin of the Nuttall Ornithological Club, vol. v. p. 3.
For the benefit of the lay reader, I ought, perhaps, to have explained before this that the Philadelphia vireo is in coloration an exact copy of the warbling vireo. There is a slight difference in size between the two, but the most practiced eye could not be depended upon to tell them apart in a tree. Vireo philadelphicus is in a peculiar case: it looks like one common bird, and sings like another. It might have been invented on purpose to circumvent collectors, as the Almighty has been supposed by some to have created fossils on purpose to deceive ungodly geologists. It is not surprising, therefore, that the bird escaped the notice of the older ornithologists. In fact, it was first described,--by Mr. Cassin,--in 1851, from a specimen taken, nine years before, near Philadelphia; and its nest remai