ENR OD) UC EEO N: XXV 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, hundreds, if not thousands, are weekly sent to the markets of the metropolis and other large towns, to which the professed wild-fowl shooter also transmits his quota of Widgeons, 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 Wood- cocks 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, form 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. Besides the species above mentioned, many other kinds, and even the eges 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 upon 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. I cannot, however, conclude the present introduction without touching lightly on some of these points, Most writers on Natural History have placed the class Aves immediately 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 swiftness 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 bollow, 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 reluctancy 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 H