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MIGRATIONS OF EUROPEAN BIRDS. 
BY A. LEITH ADAMS,, M.A.,, M.B.,, E.G.S.^ E.L.S. 
T he migrations of animals — especially those of the fea- 
thered tribes — constitute one of the most interesting 
and improving studies that the admirer of nature can pursue. 
When naturalists were less conversant with the movements 
of birds of passage^ and knew little of their habits and 
haunts,, it used to be a favourite mode of accounting for 
the regular disappearance of many species by attributing to 
them what is the case with certain animals^ namely^ a torpid 
condition during winter. It was affirmed that certain birds 
spent the cold months at the bottom of lakes,, and gravely 
asserted by an authority of the last century that swallows 
sometimes assemble in numbers^ clinging to a reed till it 
breaks and sinks with them to the bottom ; that their immer- 
sion is preceded by a song or dirge,, which lasts more than a 
quarter of an hour ; that sometimes they lay hold of a straw 
with their bills^ and plunge down in society ; and that others 
form a large mass by clinging together by the feet^ and in 
this manner commit themselves to the deep.^^ Irrespective 
of the ridiculous absurdity of such assertions,, and their want 
of corroborative evidence, we have the recorded opinions of 
John Hunter and Professor Owen as to the incompatibility of 
a bird^s organism for such a mode of existence. In all pro- 
bability, the statement may have in part arisen from the well- 
known circumstance that many birds of passage tarry in their 
summer retreats until caught by the cold of winter, when 
individuals may be found benumbed and senseless ; this is a 
common occurrence, even with the swallows and other birds 
of northern India, where in the cold months the temperature 
during night falls often to freezing, whilst at midday it may 
range as high as 80° Fahr. in the shade. I have also seen the 
green bee-eater and small warblers so much affected by a 
temperature of 40° on the banks of the Nile in Nubia as to 
be scarcely able to fly from twig to twig. The effects of 
severe winters on many of our indigenous as well as migratory 
birds have been frequently exemplified by the numbers found 
dead in sheltered situations, and especially if the cold sets in 
early, when comparatively few birds of passage escape ; for 
instance, the corncrake has been found in Britain during the 
winter months : we know of one individual that was picked 
