When once a keen-eyed naturalist was stirred
To study and define–what is a bird,
To classify by rote and book, nor fail
To mark its structure and to note the scale
Whereon its song might possibly be heard.
Thus far, no farther;–so he spake the word.
When of a sudden,–hark, the nightingale!
Oh deeper, higher than he could divine
That all-unearthly, untaught strain! He saw
The plain, brown warbler, unabashed. ‘Not mine’
(He cried) ‘the error of this fatal flaw.
No bird is this, it soars beyond my line,
Were it a bird, ‘twould answer to my law.’