94 GENERAL ORNITHOLOGY. 
bones. The numerous anchylosed (or confluent) vertebrae compose the sacrum. The haunch- 
bones or ossa innominata consist on each side of three bones, tlium, ischium, and pubis, in adult 
life more or less perfectly anchylosed. Where they all three come together is the hip-joint. 
The remaining bones, usually included among those of the body proper, are the coccygeal or 
caudal vertebree. (For anatomical detail see beyond, under Osteology, ete.) 
Topography of the Body. — Besides being thus divided into head, neck, trunk, and mem- 
bers, the exterior of the body is further subdivided or mapped out into regions for the purposes 
of description. It is necessary for the student to become familiar with the “topography” of a 
bird, as this kind of mapping out may be called, for the names of the regions or outer areas 
are incessantly used in ordinary descriptive ornithology. Many more names have been applied 
than are in common use; I shall try to define and explain all those which are usually em- 
ployed, beginning with the parts of the body, and ending with those of the members. 
L REGIONS OF THE BODY. 
Upper and Under Parts. — Draw a line from the corner of the mouth along the side of 
the head and neck to and through the shoulder-joint and thence along the side of the body to 
the root of the tail; all above this line, including the upper surfaces of the wings and tail, are 
upper parts ; all below it, including under surfaces of wings and tail, are under parts ; for 
which the short words ‘* above” and ‘‘ below” often stand. The distinction is purely arbi- 
trary, but so convenient as to be practically indispensable. Jt will be scen how an otherwise 
lengthy description, enumerating parts that lie over or under the ‘lateral line” can be 
put in so few words as, for example, ‘‘ above, green; below, yellow.” Many birds colors have 
some such simple general distribution. These parts are also the dorsal (Lat. dorsum, back) 
and ventral (Lat. venter, belly) surfaces or aspects. The upper parts of the body proper, or 
trunk, have also received the general name of noteum (Gr. varos, notos, back) ; the under parts, 
similarly restricted. that of gastreum (Gr. yaornp, gaster, belly): but these tems are not 
much used now. These two are never naked, while both head and neck may be variously bare 
of feathers. The only exception is the transient condition of certain birds during incubation, 
when, like the eider duck, they pull off feathers to furnish the nest, or when the plumage, as 
usually happens, wears off. The gastreum is rarely ornamented with feathers different in 
texture or structure from those of the plumage at large; but such a case is furnished by our 
Lewis’s woodpecker (Asyndesmus torquatus). The noteum, on the contrary, is often the seat 
of extraordinary development of feathers, either in size, shape, or texture, or all three of these 
qualities ; as the singularly elegant dorsal plumes of many herons. Individual feathers of the 
noteum are generally pennaceous, and for the most part straight and lanceolate; and asa 
whole lie smoothly shingled or imbricated. The ventral feathers are usually more largely 
plumulaceous, and less flat and imbricated, but even more compact, that is thicker, than those 
of the upper parts; especially among water birds, where they are more or less curly, and 
very thick set. There are subdivisions of the , 
Notzum.-— Beginning where the neck ends. and ending where the tail-coverts begin 
(see fig. 25, 12), this part of a bird is subdivided into back (Lat. dorstem ; fig. 25, 11) and 
rump (Lat. uropygium ; fig. 25,13). These are in direct continuation of each other, and their 
limits are not precisely defined ; the feathers of both are of the pteryla dorsalis. In general,we 
should call the anterior two-thirds or three-fourths of noteeum “ back,” and the rest “rump.” 
With the former are generally included the scapular or shoulder-feathers, scapulars or scapu- 
laries ; these are they that grow on the pteryle humerales. The region of notzeum they repre- 
sent is called scapulare (Lat. scapula, shoulder-blade), and that part of noteum strictly 
