TOPOGRAPHY OF THE BODY. 17 



iiotreum that they form is called scapulare (L. scapula, shouldcr-blacle) ; 

 that part of notieum strictly between them is called inferscajndare (lig. 4, lo) ; 

 it is often mtu'kcd, as in the chipping sparrow, with streaks or some other 

 distinguishing coloration. A part of dorsum, lying between interseapulare 

 and uropygium, is sometimes recognized as the "lower back" (L. (ergum), 

 l)ut the distinction is not practically useful. To uropygium probably also 

 belong the feathers of the ptevyloi femorales (§ 8, b), and at any rate they 

 are practically included there in descriptions ; but these properly rei)resent 

 the flanks (L. hypochondria) , that is, the sides of the rump. They are 

 sometimes the seat of peculiarly developed or otherwise modified feathers. 

 The whole of notteum, taken with the upper surfaces of the folded wings, is 

 called the "mantle" (L. stragtdum), and is often a convenient term, espec- 

 ially in describing gulls. In like manner, the 



§ 39. Gasth.eum is subdivided into regions, called, in general terms, 

 "breast" {pectus; tig. 4, at), "belly" {abdomen; fig. 4, is) and "sides of the 

 body" (fig. 4, 23). The latter Ijelong really as mucli to ijack, of course, as to 

 bell}' ; but in consequence of the underneath freighted shape of a bird's body, 

 the line we drew (§ 3G) passes so high up along the sides, that these last are 

 almost entirely given to gastrceum. The breast begins over the merr}'- 

 thought, where juguhim (§40) ends; on either hand it slopes up into 

 "sides :" behind, its extension is indefinite. Properly, it should reach as far 

 as the breast-bone {sternimi) docs ; but this Avould leave, in many birds, 

 almost nothing for abdomen, and the limit would, moreover, iluctuato 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 

 gastrseum, which we call abdomen as soon as it begins to straighten out and 

 flatten. Abdomen, like breast, rounds up on either hand into sides; behind, 

 it ends in a transverse line that passes across the anus. It has been un- 

 necessarily divided into epiigaslrium, or " pit of the stomach," and venter, 

 or "lower belly ;" but these terms are rarely used. ("C/'w,s(hk" is a word 

 constantly employed for a region immediately about the anus ; but it is 

 loosely used, sometimes including the hypochondria, and oftener meaning 

 simplj' 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, }'et a little i^nictice will enable the student to appreciate their proper 

 use in descriptions, and then use them himself Avith sufficient accurac3^ 

 The anterior continuation of hoAy 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 pterylte ; the skin is really not planted with feathers ; and partly on 

 this account, perhaps, a distinctively named region is not often expressed ; 

 Ave say simply "sides of the neck" (parauchenia, fig. 4, 9). Behind, it is 

 divided into two portions : a loAver, the "hind neck," or "scruff of the neck," 

 cervix (fig. 4, ^), adjoining the back; and an upper, the "nape of the 



KEY TO 2<. A. BI1:DS. 3. 



