214 ON THE NATURAL HISTORY OP THE NIGHTINGALE. 



and they are, moreover, always most uneasy about the period when 

 their free brethren must be upon their journeys. The truth is, I 

 believe, and as I have already stated, that secondary causes can 

 have but very little to do with the matter, further than as tending, 

 in some degree, to regulate it. The more deeply we investigate 

 the subject, the more clearly do we perceive that it is a seasonal im- 

 pulse originally implanted in these birds by the Creator, which can 

 never be reduced to any nice and delicate degree of sensitiveness to 

 external agencies. The diurnal bird migrates by night, soaring 

 aloft above every impediment which, in the dark, might intercept 

 its course near the surface ; and a wonderful and most inexplicable 

 instinct carries it due north and south, according to the season (and 

 more or less directly so, according to the species), over hundreds 

 and even thousands of miles of sea and varied continent, to the 

 identical spot where, a previous season, it had met with a due sup- 

 ply of every requisite. 



Affinity of the migrative insiifict with that which impels an animal 

 towards its home. — There is probably in this a close analogy (if it 

 be not the very same innate principle, whatever that may be) with 

 the instinct which carries a Bee home to its hive, which impels a 

 common Pigeon homeward from one extremity of Europe to ano- 

 ther, and by means of which an Ass, a Bullock, as well as many 

 other quadrupeds, have been known to return straight to their ac- 

 customed haunts, over pastures and across streams they never could 

 have traversed before, and by a nearer and very different route from 

 that by which they had been driven. It has been stated even of 

 many savages of the human race, and more particularly of some of 

 the aborigines of Australia, that they also possess this faculty, or 

 rather instinct, to a most astonishing degree of perfection ; and 

 some seemingly very incredible tales have been related of them con- 

 cerning it. How far these may be true, it is not for me here to 

 undertake to determine : I shall content myself with merely refer- 

 ring the curious to Mr. Jesse's Gleanings in Natural History ; a 

 work which will amply repay the trouble of a perusal, and in which 

 many remarkable instances of this singular phenomenon are re- 

 corded, together with some curious details upon the subject generally. 

 A Turtle from the British seas has found its way back to Ascen- 

 sion Island. — Mr. Jesse, however, related one fact, which may be 

 here quoted, as shewing that the same instinct has been observed 

 even in the gelid inhabitants of the ocean, though most naturalists 

 have been long aware of this as regards the Salmon. " Among a 

 number of Turtles which were taken upon Ascension Island, was 



