Pennant, in his solution, already mentioned, of the difficulty, by supposing two species-the migrating and the sleeping swallow. With respect to the principal objects of this wonderful instinct, that teaches such various kinds of the feathered race to migrate to different countries, it is obvious from what has alteady been said, that they are food, temperature of air, and convenient situations, for breeding. I shall, therefore, conclude this paper with the following beautiful stanzas, from an elegy by Mr. Jago, on their disappearance from this country:

Through sacred prescience, well they know
The near approach of elemental strife;
The blustry tempest, and the chilling snow,
With every want and scourge of tender life!

Thus taught, they meditate a speedy flight;

For this ev'n now they prune their vig'rous wing; For this consult, advise, prepare, excite,

And prove

their strength in many an airy ring.

No sorrow loads their breast, or swells their eye,
To quit their friendly haunts, or native home;
Nor fear they, launching on the boundless sky,
In search of future settlements to roam.

They feel a power, an impulse all divine!

That warns them hence; they feel it, and obey; To this direction all their cares resign,

Unknown their destined stage, unmarked their way!

Well fare your flight! ye mild domestic race!
Oh! for your wings to travel with the sun!
Health brace your nerves, and zephyrs aid your pace,
'Till your long voyage happily be done!

See, Delia, on my roof your guests to-day;
To-morrow on my roof your guests no more!
Ere yet 'tis night, with haste they wing away,
To-morrow lands them on some safer shore.

See an ingenious little work by Mr. Forster, on the Brvmal Retreat of the Swallow, third edition, for more on this subject.

How just the moral in this scene conveyed!
And what without a moral would we read?
Then mark what Damon tells his gentle maid,
And with his lesson register the deed.

'Tis thus life's cheerful seasons roll away;
Thus threats the winter of inclement age;
Our time of action but a summer's day :

And earth's frail orb the sadly-varied stage!
And does no power its friendly aid dispense,
Nor give us tidings of some happier clime?
Find we no guide in gracious Providence
Beyond the stroke of death, the verge of time?
Yes, yes, the sacred oracles we hear,

That point the path to realms of endless day;
That bid our hearts, nor death, nor anguish fear,
This future transport, that to life the way.

Then let us timely for our flight prepare,
And form the soul for her divine abode;
Obey the call, and trust the Leader's care
To bring us safe through virtue's paths to God.
Let no fond love for earth exact a sigh,
No doubts divert our steady steps aside;
Nor let us long to live, nor dread to die;
Heav'n is our hope, and Providence our guide.

No. LXVII.

ON MIGRATION IN GENERAL.

Atque alio patriam quærunt sub sole jacentem.

Regions they seek beneath another sun.

VIRGIL.

MIGRATION is generally supposed to be peculiar to the feathered tribe; but this is a limited idea, which has originated from inattention to the economy of Nature. Birds migrate with a view to

remedy the inconveniencies of their present situation, and to acquire a more commodious station with regard to food, temperature, propagation, and shelter; but, from similar motives, men, sometimes in amazing multitudes, have migrated from north to south, displaced the native inhabitants, and fixed establishments in more comfortable climates than those which they had relinquished; and these, in their turn, have fallen victims to fresh and barbarous emigrants. Among the inhabitants of the more northern nations, as Norway, Sweden, &c. notwithstanding a very strong attachment to their native countries, there seems to be a natural or instinctive propensity to migrate. Poverty, rigour of climate, curiosity, ambition, false representations of interested individuals, the oppression of feudal barons, and similar circumstances, have given rise to great emigrations of the human species. But it is worthy of remark, that the emigrations from south to north, except from the love of conquest in ambitious nations, are so rare, that the instinct seems hardly to exist in those more fortunate climates. Curiosity is a general instinctive principle, which operates strongly in the youthful periods of life, and stimulates every man to visit places that are distant from his ordinary residence. This innate desire is influenced by the relations of travellers, and by many other incentives of a more interested kind. Without the principle of migration, mankind, it is probable, would never have been so universally diffused over the surface of the earth. It is counterbalanced, however, by attachment to those countries which give us birth, a principle still more powerful and efficient. Love of our native country is so strong, that, after gratifying the migrating principle, almost every man feels a longing desire to return.

Savages, as long as their store of food remains unexhausted, continue in a listless inactive state, and

seem not to be prompted by any motives of curiosity. They have no conception of a man's walking either for amusement or exercise. But, when their provisions begin to fail, an astonishing reverse takes place. They then rouse, as from a profound sleep. In quest of wild beasts, birds, and fishes, they migrate to immense distances, exert the greatest feats of activity, and endure incredible hardships and fatigue. After acquiring a store of provisions, they return to their wonted haunts, and remain inactive till their food begins again to fail.

Quadrupeds likewise perform partial migrations. At the approach of winter, the stag, the reindeer, and the roebuck, leave the tops of the lofty mountains and come down to the plains and copses. Their chief objects, in these flittings, are food and shelter. When summer commences they are harassed with different species of winged insects, and to avoid these enemies, they regain the summits of the mountains, where the cold, and the height of the situation, protect them from their attacks. In Norway, and the more northern regions of Europe, the oxen, during the winter, migrate to the shores of the sea, where they feed upon sea plants and the bones of fish ; and bishop Pontoppidan remarks, that the cattle know by instinct when the tide retires, and leaves these articles of food upon the shore. In Orkney and Shetland, the sheep, for the same purposes, uniformly repair to the shore, in winter, at the ebbing of the tides. Rats, particularly those of the northern regions of Europe, appear, from time to time, in such myriads, that the inhabitants of Norway and Lapland imagine the animals fall from heaven. The celebrated Linné, who paid great attention to the economy of these migrating rats, remarked, that they appeared in Sweden periodically every eighteen or twenty years. When about to migrate, they leave their wonted abodes, and assemble together in in

conceivable numbers. In the course of their journey they make tracks in the earth of two inches in depth; and these tracks sometimes occupy a breadth of several fathoms. What is singular, the rats in their march uniformly pursue a straight line, unless they are forced to turn aside by some insurmountable obstacle. If they meet with a rock, they first try to pierce it, and, after discovering the attempt to be impracticable, they go round it, and then resume the straight line. Even a lake does not interrupt their passage; for they either traverse it in a straight line, or perish in the attempt; and if they meet with a bark or other vessel, they do not alter their directions, but climb up the one side of it and descend by the other.

Frogs, immediately after their transformation from the tadpole state, leave the water and migrate to the meadow, or marshy grounds, in quest of insects. The numbers of young frogs which suddenly make their appearance in the plains induced Rondeletius, and many other naturalists, to imagine that they were generated in the clouds, and showered down upon the earth. But if, like Mr. Derham, they had examined the situation of the place with regard to stagnating waters, and attended to the nature and transformation of the animals, they would soon have discovered the real cause of the phenomenon.

Of all migrating animals particular kinds of fishes make the longest journeys, and in the greatest numbers. The multiplication of the species, and the procuring of food, are the principal motives of their migration. The salmon, a fish which makes regular migrations, frequents the northern regions alone. It is unknown in the Mediterranean sea, and in all the rivers which fall into it. It is found in some of the rivers of France that empty themselves into the ocean. Salmons are taken in the rivers of Kamtschatka, and appear as far north as Greenland. They live both