L) SYSTEMATIC ORNITIIULOG Y.

The Scienm: of ()rn(Urology—'l‘lie .‘ -ience of ornithology may be divided into three branehes—systematic, philosophic, and economic. The systematist aims to classit'y birds according to what are appar- ently their true relationships. He is the ornithological storekeeper, and having taken an account of stock it is his duty to keep the books of the firm in order. The philosophic ornithologist accepts as a fact the statement of att'airs given him by his tellewavorker the systemat— ist, and tries to explain the wherefore and why. He is a seeker of causes. The economist is of a more practical turn of mind. He is impressed by the incalculable influence which birds exert over our agricultural interests, and the necessity for learning with exactness whether this influence is for good or evil. But let; us describe these three departments of scientific ornithology more fully.

Systematic 01'm'lho/of/y.—'l‘lie first step in the scientific study of any group of animals is to name and classify them. Orders, families, gene ‘a, species, and subspecies are to be described and arranged in what appears to be the most natural manner. Thus all the Percliing Birds, for example, are placed in the order Pas-sews, and this order is divided into numerous families—for instance. the Thrushes or family Tardz‘dw. But how are we to know which are Perehing Birds and which of the Perehing Birds are, Thrushest The systematist answers, by studying a bird's structure. Generally speaking. orders and fami- lies are based on skeletal, muscular. and visceral characters which may be termed internal cha ‘acters. Genera are based on the form of bill, feet, wings, and tail. or on external cha 'acters. while species and sub- species are based mainly on color and size. Thus all the members of a family or order agree more or less in their principal internal charac- ters: those of a genus agree in external cha‘acters. andthe indiVid- uals of a species or subspecies resemble one another in Color and size.

The object of classifi -ation is to aid us in understanding not alone the relationships of one bird to another bird, or of one family or order of birds to another family or order, or even of living to extinct birds, but also to assist us in explaining the relationships of all the classes of the animal and vegetable. kingdoms—mammals, birds, rcp— tiles. fishes—and thus down the scale to the lowest forms of life.

This. 'stematic, study of the relationships of birds has taught us that. they have been evolved from reptilian ancestors. There is much evidence in support of this fact. but the most conclusive is furnished by the discovery in the lithographic slate of Solenhoten. Bavaria, of several specimens of a remarkable fos 'l, a reptilelike bird, which has been named Arc/ulmpfer‘i/r lil/Iogra/I/u'cu. It is the earliest known direct progenitor of the great class Ares.