ON THTil NATURAL HISTORY OF THE NIGHTINGALE. 217 



the contrary. Where I reside, many Chiffchaffs are always heard 

 singing upon the first arrival of the species, very few of which ever 

 remain and breed in the neighbourhood. 



Migrative birds seem ijislinctively to know of the period when their 

 native homes become Jit for their reception. — In the former part of 

 this paper, I mentioned that as the Nightingale is said to arrive a 

 month earlier, and to depart a month later, in Italy than in 

 England, this fact would seem to countenance the supposition that 

 the species, in its migratory journeys, proceeded by slow stages over- 

 land ; but that I did not believe this to be the case, for reasons I 

 should afterwards adduce when I came to speak more particularly 

 on the migrative instinct. Now, it will be borne in mind that 

 Redwings, Fieldfares, and certain other species which winter in the 

 British islands, do not leave us until the first or second week in 

 May ; long after those resident kinds to whijh they most approxi- 

 mate have commenced breeding, and after many of them have even 

 i-eared their first brood ; and, what is more extraordinary, a number 

 of visitant Song Thrushes, which arrive annually at the same time 

 with the Redwings, also remain gregarious — as I have many times 

 noticed — until about the period when those birds disappear ; out 

 resident Song Thrushes continuing solitary throughout the winter, 

 and most of them commencing nidification early in the month of 

 March. It would seem, therefore, necessarily to follow, that these 

 birds must have an instinctive knowledge of the period when their 

 native homes become fit for their reception ; and that, consequently, 

 the more northerly these may be situate, the later in the season do 

 the birds feel an impulse to quit their winter residence. 



Most of the phenomena concerning migration quite inexplicable."^ 

 No doubt this appears very strange, hardly credible ; but so is all 

 that concerns migration, even the instinct which impels a bird to 

 proceed in the true direction, rather than in any other ; and al- 

 though it is, doubtless, flattering to human reason to endeavour to 

 explain every phenomenon upon principles we understand, in this 

 ease, as in many others connected with Natural History, it appears 

 quite useless to attempt to do so. Upon what principle of atmos- 

 pheric or other external influence can we ever hope to account for 

 the following extraordinary fact related by a high authority, Mons. 

 Temminck ? " The routes taken by water-fowl, and birds which 

 frequent marshes, depend entirely upon the course of rivers, and the 

 bearing fgisementj of the great lakes, the waters furnishing to 

 each species its proper food ; they seem to be impelled, by a wonder- 

 ful instinct, to choose for a rallying point and place of departure, 



VOL. IV. NO. XVI. Q 



