TOPOGRAPHY OF THE BODY. 17/ 
noteum that they form is called scapulare (Li. scapula, shoulder-blade) ; 
that part of noteum strictly between them is called interscapulare (fig. 4, 10) ; 
it is often marked, as in the chipping sparrow, with streaks or some other 
distinguishing coloration. A part of dorsum, lying between interscapulare 
and uropygium, is sometimes recognized as the “lower back” (L. tergum), 
but the distinction is not practically useful. To uropygium probably also 
belong the feathers of the pieryle femorales (§ 8, 6), and at any rate they 
are practically included there in descriptions; but these properly represent 
the flanks (i. hypochondria), that is, the sides of the rump. They are 
sometimes the seat of peculiarly developed or otherwise modified feathers. 
The whole of noteum, taken with the upper surfaces of the folded wings, is 
called the “mantle” (i. séragulwm), and is often a convenient term, espec- 
ially in describing gulls. In like manner, the ~ 
§ 39. Gastrawum is subdivided into regions, called, in general terms, 
“breast” (pectus; fig. 4, 24), “belly” (abdomen; fig. 4, 18) and “sides of the 
: body” (fig. 4,23). The latter belong really as much to back, of course, as to 
belly ; but in consequence of the underneath freighted shape of a bird’s body, 
the line we drew (§ 36) passes so high up along the sides, that these last are 
| _ almost entirely given to gastreum. The breast begins over the merry- 
: thought, where jugulum (§ 40) ends; on either hand it slopes up into 
“sides :” behind, its extension is indefinite. Properly, it should reach as far 
wo as the breast-bone (sternwm) does; but this would leave, in many birds, 
i almost nothing for abdomen, and the limit would, moreover, fluctuate with 
almost every family of birds, the sternum is so variable in length and shape. 
Practically, therefore, we restrict pectus to the swelling anterior part of 
gastreum, which we call abdomen as soon as it begins to straighten out and 
flatten. Abdomen, like breast, rounds up on either hand into sédes; behind, 
it ends in a transverse line that passes across the anus. It has been un- 
necessarily divided into epigastrium, or “pit of the stomach,” and venter, 
or “lower belly ;’ but these terms are rarely used. (“Crisswm” is a word 
constantly employed for a region immediately about the anus; but it is 
loosely used, sometimes including the hypochondria, and oftener meaning 
simply the under tail coverts; I refer to it again in speaking of these last.) 
Although these various boundaries seem fluctuating and not perfectly defin- 
ite, yet a little practice will enable the student to appreciate their proper 
use in descriptions, and then use them himself with sufficient accuracy. 
The anterior continuation of body in general, or the 
§ 40. Neck, is likewise subdivided into regions. Its lateral aspects (ex- 
cept in a few 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 pteryle ; the skin is really not planted with feathers; and partly on 
this account, perhaps, a distinctively named region is not often expressed ; 
we say simply “sides of the neck” (parauchenia, fig. 4,9). Behind, it is 
divided into two portions: a lower, the “hind neck,” or “scruff of the neck,” 
cervix (fig. 4, 8), adjoining the back; and an upper, the “nape of the 
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KEY TO N. A. BIRDS. 3. 
