340 GEOGRAPHICAL DISTRIBUTION 



partial distribution of the Nightingale has hitherto been pro- 

 pounded ; there is no peculiar kind of soil which it especially 

 affects, or none, so far as we know, that it especially avoids ; and 

 the same may be said of its relations to the Flora of this country. 

 It is not so entirely adscriptus glehx that it will not readily betake 

 itself to new localities suited to its liking, when these have been 

 formed within its natural limits, though they may be miles away 

 from its ancient haunts. On the contrary, it is often one of the 

 first birds to establish itself when a heath has been broken up, and 

 plantations of trees thereon made have grown sufficiently to aflford 

 it the sheltering covert that it loves. This instance taken from a 

 bird whose habits have been so closely studied both in captivity 

 and at large, and one which is so familiar and in many places so 

 numerous, that abundant opportunities are given for observing all 

 that can be observed about it, shews how futile would be the 

 expectation that in most cases we could at present, even if ever, 

 satisfactorily account for the existing causes which limit the dis- 

 tribution of species. A vast majority of them, we know, have 

 each its bounds, which virtually it cannot pass, and the case of the 

 Nightingale in England, beyond the fact that its distribution is 

 extremely well marked, and therefore has long attracted especial 

 attention, has really nothing out of the common way in it.^ In 

 Europe, the neighbourhood of Copenhagen is the most northern 

 point which our Nightingale is asserted to reach ; but on the 

 continent its range is less extended, and though abundant in 

 Mecklenburg, it is not found in that part of Pomerania which lies 

 to the north of the Peene valley, nor does it stretch so far eastward 

 as Danzig.^ It occurs, however, sparingly on the Polish frontier, 

 near Thorn, and is observed in Austria, Upper Hungary, and 

 Galizia. In Russia its distribution cannot be laid down with any 

 degree of accuracy, but it does not reach the Governments near 

 the Ural, though it is said to be 'plentiful in that of Kharkov, and 

 it is known to Adsit the Crimea. Records of its occurrence still 

 further to the eastward are probably incorrect, as it seems to be 



^ When the history of the earth shall be really well and minutely under- 

 stood, it seems quite possible that as much light will be shed on this and other 

 particular cases of the same kind by a knowledge of the various changes and 

 displacements which sea and land have undergone as has already been done by 

 the same means in regard to many of the general facts of Distribution. The 

 results of the labour of the geologist are doubtless just as necessary to and 

 closely connected with the work of the biologist, as those of the investigation of 

 the historian are to and with the efficiency of the statesman ; while, in return, 

 the researches of the biologist are, or ought to be, of the greatest use to the 

 geologist. The history of the earth is for a long period of time that of its 

 inhabitants. 



2 From the Rhine valley eastward the range of the other European species 

 overlaps that of the present. 



