CORDEAUX: ADDRESS TO YORKSHIRE NATURALISTS. 203 
mences in July, and continues to the middle of November; they 
pass the North Sea in a S.W. direction in a broad front, one wing of 
which touches the Shetlands, and the other the north coast of Norfolk. 
Then there is the east to west route, chiefly used by day migrants, 
and composed of birds such as are generally ranked as partial 
migrants. This immigration commences late in September, across 
the more southern parts of the North Sea, from E. to W. or S.E. to 
N.W., and often covers the coast line as far north as the Tees mouth 
and beyond ; another stream of this E. to W. movement passes along 
the south coast, and, finally, into south-east Ireland, and further still, 
as in the case of larks, which are shown to travel northward, up the 
Irish Channel, to the Hebrides. Again, from the end of July to the 
middle of November, there is a great emigration of both summer 
visitors and partial migrants from N.W. to S.E., from the coasts 
the south-eastern counties ; these emigrants, in many instances, being 
composed of the very same species which are, at the same time, 
entering the country by the E. to W. route. 
In the spring, birds return from the same sections of the eastern 
Seaboard, to their summer quarters, as witnessed their arrival in the 
_ In the autumn, we are aware that enormous numbers of various 
pass Heligoland by an E. to W. route, but we have no proof 
that they come across the North Sea in the same latitude, although 
digest, which fills a closely-printed pamphlet of twenty-seven pages, 
every line of which is worthy of consideration. It cannot be doubted 
that, henceforth, as regards the British islands, there is now estab- 
_ lished a firm basis on which may rest a sound, a proper conception 
of many of the phenomena of British migration. eee 
to be extracted from the enormous mass of information now 
teduced to order. 
July 1807. 
