352 THE STRUCTURE AND LIFE OF BIRDS CHAP. 
for some species, of the southern region for others. 
There is also an cast and west migration of ‘which I 
shall speak soon. 
It is vain to search the animal kingdom for other 
migrations on so great a scale as those of birds. The 
movements of fish afford the nearest parallel, for they 
occur annually at regular seasons and are connected 
with reproduction. At a certain season every year 
the salmon betakes him to his river, and the herring 
and the mackerel move towards the coast. These, 
though far less wonderful than the regularly recurring 
movements of birds, are true migrations. But when 
the monkeys in the Himalayas ascend to a height of 
10,000 feet or more in summer, or when the lemmings 
in Norway, at long and irregular intervals, sweep like 
a great flood towards the sea, they do not, in the 
strict sense, migrate. 
The Distances Covered. 
The Sanderling nests in Iceland or on the shores of 
the Arctic Ocean, and in winter it has been seen as 
far south as Cape Colony. The nestlings of the Knot 
have been found in Grinnell Land in lat. 82° 33’ N, 
and the bird is known to winter as far south as 
Australia and New Zealand. The Turnstone is a 
great traveller, nesting in Greenland or the coasts of 
Scandinavia, and wintering in Australia, New Zealand, 
South America, or Africa. The distances travelled 
amount sometimes to over 7,000 miles.!| The dim- 
inutive size of a bird is no evidence at all that he is 
' Mr, Seebohm puts the longest at 10,000 miles. 
