ITS FOOD. 375 
winter, and these are joined by great numbers from 
the southin March, when they all retire to the rugged 
banks of the river Mint to spend the season of in- 
cubation.” A remarkable feature in the habits and 
economy of birds is their adaptation of appetite to 
a variety of food, both as regards one season or 
time, and as regards various seasons, in which we 
frequently notice a change in theirfood. But few 
of the class confine themselves to one particular 
species of food, whereas a very large proportion 
partake of a variety, but still not similar in charac- 
ter. Thus, the Grey Wagtail searches out various 
insects, and is content to feed on such as are found 
on the shore, which necessarily must differ widely 
from those inhabiting the sides of rivers or of 
streamlets. Very many birds again, have appetites 
still more accommodating, and will devour food 
quite incongruous. ‘This portion of the economy of 
the Grey Wagtail permits the extension of the 
species much more than would otherwise be effect- 
ed, and we see also that it even protects the species 
to a great extent from death, for ifit could not on 
emergency betake itself to the food afforded by the 
roads when frost deprives it of more genial sup- 
plies, it must necessarily be the victim of want. We 
conclude also, that it is this principle of accommo- 
dation in the appetites and digestive powers of birds 
and other creatures, which fits and enables them to 
live in the midst of alterations in their ordinary 
provender effected by the operations of man, and 
which permits us to avail ourselves of their ser- 
vices in a domesticated or reclaimed state without 
much trouble or inconvenience, their appetites 
shortly becoming adapted to an unaccustomed diet. 
And so, in their habits and actions we must not fail 
to note a principle of accommodation of the same 
description. _A little reflection must bring to our 
minds a thousand alterations in the face of Nature 
