KATUUAL HISTORY OF SELBORNE. 57 
violent piece of machinery : it is a difficulty worthy of the interposition 
of a god ! " Incredulus odi." ^ 
TO THOMAS PENNANT, ESQUIRE. 
THE JSTATURALIST'S SUMMER-EYENIXG WALK. 
-. equidem credo, quia sit divinitus illis 
Ingeiiium. ViRG. Georg. 
When day declining sheds a milder gleam, 
What time the may-fly f haunts 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 the vale, 
And listen to the vagrant J cuckoo's tale ; 
To hear the clamorous § curlew call his mate, - 
Or the soft quail his tender pain relate ; 
To see the swallow sweep the dark'ning plain 
Belated, to support her infant train ; 
To mark the swift in rapid giddy ring 
Dash round the steeple, unsubdued of wing : 
Amusive birds ! — say where your hid retreat 
When the frost rages and the tempests beat ; 
Whence your return, by such nice instinct led, 
When spring, soft season, lifts her bloomy head 1 
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, 
* The zoology of the New World is essentially distinct from that of the old, so 
is that of Africa from India, and both the latter from those of Austra lia and the 
Pacific. There may be a few forms common to some of these divisions, but the 
great type of the zoology of each is distinct. That of the western coast of A frica 
is quite distinct from that of America; among the birds, for instance, which 
possess the greatest amount of locomotive power, none of the migratory species 
travel from continent to continent, and the generic forms even are almost entirely 
different. In later times, where there is a much more frequent communication 
between Europe and the west coast of Africa, and by means of the slave trade 
between that country and South America and the West Indian islands, there have 
been various introductions from the one country to the other, and particularly of 
the Vegetable Kingdom, but even with these the great mass of both Fauna and Flora 
continue distinct. There is no more interesting study than that of the geographical 
distribution of animals and plants, and of the very remarkable incidents which 
sometimes occur to effect the transportation of some which are almost entirely 
without the power of crossing seas or oceans. 
t The angler's may-fly, the ephemera vulgata Linn., comes forth from its aurella 
state, and emerges out of the water about six in the evening, and dies about eleven 
at night, determining the date of its fly state in about five or six hours. They 
usually begin to appear about the 4th of J une, and continue in succession for 
near a fortnight. See Swammerdam, Derham, Scoiooli, &c. 
X Vagrant cuckoo ; so called because, being tied down by no incubation or 
attendance about the nutrition of its young, it wanders without control. 
§ Charadrms oedicnemus. 
