MIGRATION OF BIRDS 
225 
in the very early morning, which species were certainly not 
in the neighbourhood the evening before. 
Other evidence against landmarks is the fact that birds 
can travel over large tracts of ocean. 
Some individuals do get blown out of their proper course 
and turn up at unexpected places — such, for example, as 
American species occurring on the east coast of Britain. 
With regard to the suggestion of high development of 
sense of locality and direction, one would certainly think 
that this was well exemplified in the case of ‘ homing pigeons ’ ; 
but we are informed by authorities on these birds that the 
ability to travel long distances without losing their way is 
purely due to recognition of landmarks. 
Routes . — According to the observations of certain Russian 
and German ornithologists, migration-routes follow more or 
less horizontal lines, but the configuration of the land influences 
the routes very largely. Thus birds will follow the course 
of rivers and skirt mountain ranges. 
Of the various routes shown on the map 1 I exhibit, com- 
paratively few interest us directly ; for the purposes of this 
paper it can be taken that the eastern routes are those by 
which birds come to and go from this country. There are 
of course exceptions ( cf . specimens of Swifts and Western 
Nightingale). Most species, after having crossed the European 
or Asiatic countries, pass across to Africa, travelling either 
down the east coast or down the Valley of the Nile, to this 
country or even on to the Cape. 
Rate of Travelling . — The rate at which birds travel while 
on migration has been calculated by a German observer to 
be 200 miles an hour. This seems incredible, but may be 
true for short- distance flights. But could the birds keep this 
speed up for any time ? Experiment shows the rate to be 
about thirty-eight miles per hour, but this was under artificial 
conditions. I have no doubt that birds travel at the most 
favourable time, and that they take advantage of air-currents 
to help them on. 
I shall hope to show later on, by means of actual specimens, 
that individuals of certain migratory species do not leave 
1 Not reproduced in this Journal. 
