96 GENERAL OBNITHOLOGY. 



the merry-thought where juguluin (see beyond) ends; on either hand, it slopes up to " sides"; 

 behind, its extension is indefinite. It should properly reach as far as the breast-bone does, to 

 the limit of the thorax ; but in many birds this would leave almost nothing for abdomen, and 

 the limit would moreover fluctuate with almost every family of birds, the sternum being so 

 variable in length. Practically, therefore, without reference to the breast-bone, "breast" or 

 pectus is restricted to the swelling anterior part of gastrseum, which we call beUy or abdomen 

 as soon as it begins to straighten out and ilatten. Abdomen, like pectus, rounds up on either 

 hand into sides ; behind, it ends definitely in a transverse hne passing across the anus. It has 

 been unnecessarily divided into epigastrium or " pit of the stomach," and venter or Ibwer belly ; 

 but these terms are rarely used. (Crissum is a word constantly used for some indefinite region 

 immediately about the vent ; sometimes meaning the flanks, sometimes the vent-feathers or 

 under tail-coverts proper ; I refer to it again in connection with these last.) Though these 

 boundaries seem fluctuating and not perfectly satisfactory, a little practice wiU enable the 

 student to appreciate their proper use in descriptions, and to employ them himself with suffi- • 

 cient accuracy. The ad.jeotival terms are respectively pectoral, abdomimal, and lateral. The 

 anterior continuation of the trunk, or the 



Neck (Lat. collum) is likewise subdivided into regions. Its lateral aspects, except in 

 those birds that have lateral neck-tracts of feathers, are formed by the meeting over its sides 

 of the feathers that grow on the dorsal and ventral pterylse, the skin being usually not planted 

 with feathers. Partly on this account, perhaps, a distinctively named region is not often 

 expressed; we say simply "sides of the neck," or -'neck laterally" (parauchenia, fig. 25, 9). 

 The neck behind, or the dorsal (upper) aspect, is divided into two portions : a lower, the 

 "hind neck" proper, or "scruff of the neck" (Lat. cervix; fig. 35, 8), next to the back; 

 and an upper, or "nape of the neck" (Lat. nucha; fig. 25, 7), adjoining the hind head. 

 These are otherwise respectively known as the cervical and nuchal region ; and, in speaking 

 of both together, we usually say "the neck behind." The front of the neck has been need- 

 lessly subdivided, and these subregions vary with almost every writer. It sufiSces to call it 

 throat (Lat. gula, fig. 25, 37, or jugulum, 34) ; remembering that the jugular portion is 

 lowermost, vanishing in breast, and the gular uppermost, running into chin along the under 

 surface of the head. Gutbwr is a term sometimes used to include gula and jugulum together : 

 it is simply equivalent to " throat," as just defined ; the adjective is guttural. Though gener- 

 ally covered with feathers, the neck, unlike the trunk, is frequently partly naked. When naked 

 behind, it is usually cervix that is bare, as so characteristically occurs in herons, from interrup- 

 tion of the forward extension of the pteryla spinalis. Nucha is seldom if ever naked, except as 

 an extension of general bald-headedness. (xula is siinilarly naked from above downwards, as 

 conspicuously illustrated in the order Steganopodes, comprising the pelicans, cormorants, etc., 

 which have a bare gular pouch ; and as seen in many vultures, whose baldness extends over 

 nucha and gula,. and even all around the neck, as in the condor, whose nakedness ends with so 

 singular a collar of close-set, downy feathers. The lower throat or jugulum becomes naked 

 in a few birds, in which a distended crop or craw protrudes, pushing apart feathers of two 

 branches of the pteryla ventralis as these ascend the neck. The rule is, that the neck is not 

 the seat of enlarged or otherwise highly developed feathers, which might restrict the requisite 

 freedom of its motion ; but there are some signal exceptions, among which may be instanced 

 the grouse family. The ruffed grouse has a singular umbrella-like tuft on each side of th" ■•^.p^\ : 

 the pinnated grouse has still more curious vringlets in the same situation, covering bare disten- 

 sible skin : the sharp-tailed grouse is in somewhat similar but less pronounced case ; while the 

 cock of the plains has some extraordinary jugular developments of feathers in connection with 

 his subcutaneous tympanum. Cervix proper almost never has modified feathers, bu;t often a 

 transverse coloration different from that of the rest of the upper parts ; when conspictious, this 



