95 
It is quite impossible to give au estimate of the numbers of wild 
Ducks and Geese that are yearly consumed in the three kingdoms ; 
but that they are immense will be readily conceived when it is 
stated that from the various decoys, and from the Continent, hun- 
dreds, if not thousands, are weekly sent to the markets of the metro- 
polis and other large towns, to which the professed wild-fowl shooter 
also transmits his quota of Wigeons, Pochards, and Brent Geese. 
The Common Pewit and the Golden Plover are largely consumed, as 
are also the Stints and other strand-loving birds. The supply of 
Snipes and Woodcocks is dependent in a great measure upon the nature 
of the season, as is also, to a certain extent, that of the Wood-Pigeon, 
the Partridge, the Grouse, the Pheasant and other game-birds. The 
Dottrel, which passes over our islands from south to north during 
the month of May, is subjected to a large annual toll, and, with the 
imported and fattened Quail and the Ortolans, forms delicate viands 
for the tables of the wealthy and of the epicures who require such 
whets for their appetites, and who can afford their purchase. Be- 
sides the species above mentioned, many other kinds, and even the eggs 
of several, are diligently sought for; those of the Lapwing, Black- 
headed Gulls, and Guillemots, especially the former, being in great 
request. These remarks may appear trite, but they serve to show 
that many of our birds are extensively utilized. 
Much has been written upon the classification, general structure, 
power of flight, and senses of birds; but were I to go into detail on 
these matters I should only be reproducing what has been so ably 
treated by such men as Macgillivray, Owen, Jerdon, Flower, Huxley, 
Parker, and others. J cannot, however, conclude the present intro- 
duction without touching lightly on some of these points. 
Most writers on Natural History have placed the class Aves imme- 
diately above the Reptiles and below the Mammals, from either of 
which they are clearly separated by the distinctive characteristics 
shown in their general form, habits, feathered covering, and powers 
of flight. It is in regard to some of these that I would now wish 
to say a few words. All those who have studied the anatomy of 
birds, even but cursorily, must have become specially aware of the 
wonderful adaptation shown by nature in fashioning the skeleton so 
as to enable the creature to support itself in the air with the least 
possible exertion, and propel its body with varying degrees of swift- 
ness through that element; they will have noticed that this power of 
flight is aided to a considerable extent by the fact of the bones being 
hollow, and their cavities communicating for the most part with the 
cells of the lungs—a provision ensuring the maximum of strength 
with the minimum of weight. 
The wings of birds modify in various ways the velocity with 
which they are capable of cleaving the air. Some, like the Land- 
Rail and the Bittern, with rounded wings, evince considerable reluct- 
ancy to quit the ground, and, when they do so, merely fly to a short 
distance; others, such as the Auks and Penguins, have, indeed, but 
the rudiments of those organs; while others, again, have their wings 
and pectoral muscles developed to such an extent that extraordinary 
