[138] In the preparation of this chapter, the author begs to acknowledge the assistance he has received from his friend Professor F. Jeffrey Bell, B.A.
[139] These lines are thus translated by Mr. Hayward:—“I hurry on to drink his everlasting light—the day before me and the night behind—the heavens above, and under me the waves. A glorious dream! as it is passing, he is gone. Alas! no bodily wing will so easily keep pace with the wings of the mind! Yet it is the inborn tendency of our being for feeling to strive upwards and onwards; when, over us, lost in the blue expanse the lark sings its thrilling lay; when, over rugged pine-covered heights, the out-spread eagle soars; and, over marsh and sea, the crane struggles onward to her home.”
[140] These plates may become united with one another in the middle line, and the birds that possess this arrangement have been called Desmognathæ (δεσμός, “a bond;” γνάθος, “jaw”); or they may be separated by a more or less narrow cleft, in which case the birds in which this is found are called Schizognathæ (σχίζω, “I cleave”). As a matter of fact, the term Schizognathous is confined to those birds in which the above-mentioned vomer is pointed in front, while where it is truncated the birds are called Ægithognathæ (αἴγιθος, “a sparrow,” as the character is seen in these birds). In these groups, however, the Ostriches, or running birds, which are distinguished by having no keel to their sternum, are not included; nor in them is the vomer narrow behind. This broad character of the hinder end of the vomer is seen also in one group of birds with a keeled sternum—the Tinamous—which are consequently distinguished from other “Carinate” birds by the term Dromæognathæ (Dromæus, the Emu).
[141] The presence or absence of it, or of the other muscles, is used as a means for arranging the smaller divisions of the larger groups into which the two first-named sub-classes are, by the aid of other anatomical facts, divided. One striking advantage of this system, as suggested by the late Prof. A. H. Garrod, is that the characters of the ambiens have been observed to go hand in hand with certain other characters. Thus, the cæca found at the end of the small intestine are always present in the Homalogonatæ, or birds having the normal arrangement of knee-muscles; but in this connection there is another structure to be mentioned, namely, the so-called oil-gland, or gland by the secretion of which the bird “preens” its feathers, and which is always set in the skin in the region of the tail. Now this “uropygial,” or oil-gland, may or may not be provided with a tuft of feathers, and as there may or may not be cæca to the intestine, it follows that—(1) the gland may be tufted and there may be cæca, or (2) the gland may have no feathers and cæca may be present, or (3) there may be no cæca and a tufted gland, or (4) there may be no cæca and no tufts (the possible arrangement of neither being present is found in a few Pigeons). But this is not the place to follow out the details of this classification.
With regard to the proposition made by a French observer, M. Alix, that birds should be divided into the Homœomyarii, Entomyarii, and Ectomyarii, according to the character of certain of the flexor muscles at the back of the leg, it seems only necessary to remark that so far anatomical investigations have not supported his views, while his system would separate birds which seem to be closely allied.
[142] Compare Vol. I., p. 213
[143] Accipitres diurni of authors.
[144] Accipitres nocturni of authors.
[145] Machærhamphus Anderssoni.
[146] Accipitrinæ.