26 INTRODUCTION. 



sacral, of which the number can be determined only by count- 

 ing the foramina by which the spinal nerves issue, vary from 

 seven to twenty, and in the Golden Eagle are eleven. 



The caudal or coccygeal vertebra3, g^ vary from six to nine, 

 and in the present bird are eight. They are narrow, generally 

 mobile, with superior and inferior spinous, and frequently with 

 transverse processes. The last bone is much larger, of an ir- 

 regular oblong form, without processes, much compressed ; and 

 affords a basis to the tail-feathers. 



The Body, properly so called, is composed of the dorsal, 

 sacral, and coccygeal parts of the vertebral column above, 

 laterally of the ribs and pelvis, and beneath, of the sternum, 

 together with the soft parts contained in it, and those without. 

 Its anterior part is named the thorax, the posterior the pelvis. 

 The Thorax is composed of the dorsal vertebrae, the ribs, and 

 the sternum. It contains the heart, the lungs, the liver, the 

 lower part of the oesophagus, and a portion of the intestine, be- 

 sides vessels and nerves. The ribs, k, k^ w, n^ vary in number 

 from six to eleven, and in the Golden Eagle are eight. That part 

 of them which is nearest the sternum, m, is not cartilaginous, as 

 in the Mammalia, but bony, whence two sets of ribs are de- 

 scribed by authors, the dorsal and the sternal. In plain lan- 

 guage, each rib is divided into two parts, one, ^, attached to 

 the dorsal vertebrae, the other, m^ to the sternum, both meeting 

 with a moveable articulation, k. The ribs have two attach- 

 ments to the vertebrae, one by their head 

 to the body, the other by the angle to the 

 transverse process. From about the mid- 

 dle of their dorsal or upper portion, a thin 

 slender process, n^ n^ passes obliquely up- 

 wards and backwards, over the next rib 

 behind, by which the strength of the tho- 

 rax is obviously augmented. These pro- 

 cesses do not exist on the first rib, which 

 is generally incomplete below, nor on the 



Fig. 3. Rihs of Golden Eagle. ][^g^^ whcrO it WOuld be USclcSS. 



Fig. 3 represents two ribs of the GoldenEagle : — «, a, the 

 vertebral portion ; h, h. the sternal portion ; c, c, the angle or 



