212 ON THE NATURAL HISTORY OP THE NIGHTINGALE. 



as portions of the Creator's institutions, and when the husy scenes 

 of life shall be so arranged as to become a field for the practice at 

 once of our philosophy and our religion — then, after a long train of 

 gradual advances, will man assume his high station as an intelligent 

 and responsible being — then will the ascendancy of virtue and reli- 

 gion be more complete — and then will Christianity achieve her 

 noblest triumph, and flourish, ever brightening, most glorious and 

 immortal. J. K. 



On THE NATURAL HISTORY op the NIGHTINGALE, 



(Philomela luscinia, — Swainson ;) 

 By Edward Blyth, Esq., Tooting, Surrey. 



[Concluded from our last number.] 



What agencies affect the development of the migrative impulse. — 

 In matters of Natural History, nothing is more difficult than to 

 arrive at sound general conclusions, to deduce universal laws, which 

 shall not be liable to certain exceptions. It is so with the migra- 

 tion of birds, at least when we would attempt to refer the develop- 

 ment of the migrative instinct to the mere agency of internal im- 

 pressions. Thus, in most of the species (as in the Nightingale), 

 the migratory impulse would seem, at least to all appearance, to be 

 chiefly, if not wholly, influenced by change of temperature ; in 

 others (as in the common Grey Flycatcher), deficiency of food would 

 seem also to be a predisposing cause; while others again (as the 

 Cuckoo and the Swift) retire southward, as has been already men- 

 tioned, at the very hottest season of the year, and when their food 

 would seem to be most abundant. The adult Cuckoos even leave 

 us when in full moult, though none of the flying feathers, by the 

 way, are shed till after they have left us ; and so powerful is the 

 migrative feeling in the common Swift, that this species has been 

 several times known actually to forsake a late brood of half-fledged 

 nestlings to leave the country. All the migratory small land birds 

 perform their long journeys by night, choosing moonlight nights, 

 and starting immediately as the moon rises. It is early in the 

 morning only that they are observed to settle on the rigging of 



