78 
THE NATURAL HISTORY 
[LETT. 
Ingenious men will readily advance plausible arguments to 
support whatever theory they shall choose to maintain ; but then 
the misfortune i3, every one's hypothesis is each as good as 
another's, since they are all founded on conjecture. The late 
writers of this sort, in whom may be seen all the arguments of 
those that have gone before, as I remember, stock America from 
the western coast of Africa and the south of Europe; and then 
break down the Isthmus that bridged over the Atlantic. But 
this is making use of a violent piece of machinery : it is a difh- 
culty worthy of the interposition of a god ! " Incredulus odi." 
" I feel disgusted and disbelieving." 
THE NATURALISTS SUMMER-EVENING WALK. 
" equideiii credo, quia sit divinitus illis 
Iiigeuium." ^ — Yirg. Georg. i. 415, 416. 
When day dechiiiiig sheds a milder gleam, 
What time the May-fly liauiits the pool or stream ; 
When the still owl skims round the grassy mead, 
What time the timorous hare limps forth to feed : 
Then be the time to steal adown tlie vak^, 
zVnd listen to the vagrant cuckoo's tale ; 
To hear the clamorous curlew call his mate, 
Or the soft cpiail his tender pain relate ; 
To see the swallow sweep the dark'ning plain 
Behited, to support her infant train ; 
To mark the swift in rapid giddy ring 
Dash round the steeple, unsubdued of wiug : 
Amusive birds ! say where your hid retreat 
When the frost rages and the tempests Ijeat ; 
Whence your return, by such nice instinct led, 
When spring, soft season, lifts her bloomy head I 
Such baffled searches mock man's prying pride, 
The God of Nature is your secret guide ! 
While deep'ning shades obscure the face of day 
To yonder bench leaf-shelter'd let us stray, 
'Till blended objects fail the swimming sight, 
And all the fading landscape sinks in night ; 
To hear the drowsy dorr come Imishing by 
With buzzing wing, or the shrill cricket ^ cry ; 
^ " I think their instinct is divinely bestowed." 
- Charadrius oedicneviiis. ^ GryUiis cam2)esfris. 
