96 
GENEBAL ORNITHOLOGY. 
the merry-thought where jugulum (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 belly oi" abdomen 
as soon as it begins to straighten out and flatten. Abdomen, like pectus, rounds up on either 
hand into sides ; behind, it ends definitely in a transverse line passing across the anus. It has 
been unnecessarily divided into epigastrium or pit of the stomach," and venter or lower belly; 
but these terms are rarely used. {Orissum 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 will enable the 
student to appreciate their proper use in descriptions, and to employ them himself with suffi- 
cient accuracy. The adjectival terms are respectively pectoral, abdominal, 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 meetihg 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. 25, 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 suffices 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. Guttur 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. Gula is similarly 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, do\vny 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 the neck : 
the pinnated grouse has still more curious winglets 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, but often a 
transverse coloration different from that of the rest of the upper parts ; when conspicuous, this 
