98 GENERAL ORNITHOLOGY. 



modified feathers. In Woodcock and Snipe, owing to the way the brain-box is tilted up, the 

 ears are below and not behind the eyes. The mouth (Lat. os, gen. oris) is always a fissure across 

 the front of the head. The cleavage varies, both in extent and direction ; the latter is usually 

 horizontal, or nearly so, but may trend much downward ; the former varies from a minimum, 

 in which the cleft does not reach back of the horny part of the bill, as in a snipe, to the maxi- 

 mum seen in fissure-billed birds like Swifts and Goatsuckers, which gape almost from ear to ear. 

 There are no other openings in the head proper, for the nostrils are always in the bill. 



The Neck, in effect, is a simple cylinder, rendered somewhat hour-glass shaped, as above 

 said. It consists of a movable chain of bones, or cervical vertebrae (Lat. cervix, neck ; verto, I 

 turn), enveloped in muscle, along which in front lie the gullet (Lat. cesoplmgus) and windpipe 

 (Lat. trachea), with associate blood-vessels, nerves, etc. Its length is very variable, as is the 

 number of its bones, the latter ranging from 8 to about 26. Bearing as it does the head, with 

 the bill, which serves as a hand, the neck is extremely flexible, to permit necessarily varied 

 movements of this handy member. Its least length may be that which allows the point of a 

 bird's beak to reach the oil-gland on the rump ; its greatest length sometimes exceeds that of 

 the body and tail together, as in the case of a Swan, Crane, or Heron. The length is usually 

 in direct proportion to that of the legs, in obvious design of allowing the beak to touch the 

 ground easily to pick up food. The neck is habitually carried in a double curve, like an open 

 S or italic/, the lower belly of the curve, convex forward, fitting in between the forks of the 

 merry-thought (J^sX. fiirculum) , the upper curve, convex forward, holding the head horizontal 

 at the same time. This '' sigmoid flexure" (sigma, Greek S), highly characteristic of a bird's 

 neck, is produced by saddle-shaping of the articular surfaces of nearly all its bones. The me- 

 chanical arrangement is such, that the sigma may be easily bent till the upper end (head) rests 

 on the lower convexity, or as easily straightened to a right line ; but little if any farther devi- 

 ation in opposite curvature is permitted. As a generalization, the neck may be called relatively 

 longest in wading birds, as Herons, Cranes, Ibises, etc. ; shortest in perching birds, as the great 

 majority of small Tnsessores ; intermediate in swimming birds. But many swimmers, as 

 Swans and Cormorants, have extremely long necks ; and some waders, as Plovers, have very 

 short ones. A long neck is a rarity among higher birds (above Gallince), in most of which 

 the head seems to nestle upon the shoulders. The longer the neck, the more sinuous and 

 flexible is it likely to be. Anatomically, the neck ends in front at the articulation of the atlas 

 (first cervical vertebra) with the skull, and behind at the first vertebra which bears free jointed 

 ribs reaching the sternum. The shape of 



The Body proper, or Trunk, is obviously referable to that of an egg ; it is ovate (Lat. ovum^ 

 an egg ; whence oval, the plane figure represented by the middle lengthwise section of an egg; 

 ovate or ovoid, the solid figure). The swelling of the breast represents the greatest diameter of 

 the egg, usually near the larger end. But an ovoid is never perfectly expressed, and departures 

 from such figure are numberless. In general, perching birds have the body nearly of ovate 

 shape ; among waders, the figure is usually compressed, or flattened vertically, as is well seen 

 in Herons, and still better in Rails, where the lateral narrowing is at an extreme ; among swim- 

 mers, the body is always more or less depressed, or flattened horizontally, and especially under- 

 neath, tliat the birds may rest on water with more stability, as well shown by a Duck or Diver. 

 Anatomically the body begins with the foremost one of the dorsal vertebrce, or those that bear 

 true ribs; laterally, it ceases quite definitely at the shoulder -joints, the whole fore limb being 

 outside the general content of the trunk ; behind, in mid-line, it includes everything, only the 

 Xa\\-feathers themselves being beyond it; behind and laterally, it includes more or less of the 

 legs, for these are generally buried in common integument of the body nearly or quite to 

 the knee-joint, sometimes to the heel-joint; though in anatomical strictness the trunk is 



