LESSER WHITETHROAT 
on the shores of Loch Lomond, and both of these again differ 
in this respect from the same bird in the Island of Texel. 
The Wren in Worcestershire has a different song from that 
of the Wren in Donegal and Sark, and the Willow Warblers 
that grace the banks of the Danube can be readily distin- 
euished by their notes from those in this country. 
The subject is one of some difficulty, and is further 
complicated by our having to rely solely on so delicate an 
instrument as the human ear. But it should be our first aim, 
no matter what the problem with which we are confronted in 
Nature, to attempt to find some one characteristic which 
extends to every case, or at any rate obtains in a large number 
of them, and upon which we can base our further investiga- 
tions. This, I believe, we can do in the present instance, 
always, however, bearing in mind the imperfections to which 
the human ear is liable. 
If we take the Midland counties as our starting-point, and 
from thence journey in a westerly or south-westerly direc- 
tion, we shall find that as we approach the coast of Wales, 
or of the south-western counties, the tendency is for the 
pitch of the song of many species to become gradually lower. 
But passing over these slight differences, we will still continue 
west, across the Irish Sea and across Ireland, until we finally 
reach the West of Donegal, where, having selected the song 
of one of the more common species, we will proceed to make 
comparisons with that of the same species in any one of the 
counties from which we started. Well, to my ear there is no 
doubt about the difference; the Blackbird pipes in a lower 
key, the cheery song of the Wren is more mellow, and even 
the familiar call note of the Chaffinch has gained some subtle 
difference. Leaving this, however, we will return to our 
starting-point, and journey in a southerly direction until we 
reach the Channel Islands. Here we shall find the same con- 
ditions prevailing asin Donegal—namely, a uniform lowering 
of the pitch; and yet again comparisons made on the west 
coast, or even on parts of the north-east coast of Scotland, will 
17 
