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 glebe 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 afford 
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 visit the Crimea. Records of its occurrence still 
further to the eastward are probably incorrect, as it seems to be 
1 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. 
