90 ANATOMICAL TECSNOLOGY. 



crum, while the caudal vertebrse extend caiadad of the last-named 

 bone. 



The first and second cervical vertebrae (Fig. 52), are also called, 

 respectively, atlas and axis. The former is expanded laterally in 

 wide transverse processes. The latter presents a Spina neuralis, 

 which is both long and high. 



The seventh cervical spine and the first five thoracic are hidden 

 in Fig. 30. The first nine or ten thoracic spines are dii'ected more 

 or less decidedly caudad, but the last two or three, like the lum- 

 bar, are directed cephalad, whUe the tenth or eleventh has an inter- 

 mediate direction. The various processes become less and less dis- 

 tinct among the caudal vertebrae, and the caudal members of the 

 series ai-e little more than subcylindrical segments of bone. 



Unlike most anatomists, Straus-Durckheim includes (B, I., 480, PI. xi., B, (J), the 

 eleventh, twelfth and thirteenth thoracic vertebrae with the lumbar series. 



§ 209. Costae — (Fig. 50). — Each cosia (rib) is seen to be con- 

 nected by its dorsal end with the thoracic region of the Golumna 

 vertebralis, and at its ventral with a costicartilago. Part of the first 

 costicartilage appears in Fig. 30 just cephalad of the left shoulder 

 joint, but the second rib and its cartilage are wholly concealed by 

 the scapula and humerus. 



§ 210. Sternum — (Fig. 49). — The sternum, or breast-bone, con- 

 sists of a series of eight or nine mesal segments called sternebrcB. 

 The caudal piece is the xiphisternum or Ctl. ensiformis, and is 

 partly cartilaginous. Tlie cephalic segment is the prcesternum or 

 manubrium, and the intervening six or seven sternebrse constitute 

 the mesosternum. 



§ 211. Scapula — shoulder blade— (Fig. 43-45).— The ectal as- 

 pect of this bone, as shown in Fig. 30 and 44, presents a ridge, 

 the mesoscapula, which has three prominences — acromion, meta- 

 cromion, and tuberositas. 



§ 212. Clavicula — The clavicle or collar bone — (Fig. 48). — In 

 the cat these bones are small and imbedded in the muscles, with- 

 out direct attachment to other bones. Tliey are shown in Fig. 30, 

 one on each side, between the shoulder joints. 



A. In the cat the scapula appears as a part of the arm. In man, however, and in many 

 other vertebrates, the clavicles are larger and articulated with the scapulae and the 

 sternum. In most reptiles and birds, and in two Mammals {Echidna and Ornithorhynchxis) 

 the scapula and the sternum are connected by a stout osseous bar — ^the coracoid — which is 

 represented in the cat as in man by merely a process — the Pre. coracoideus ; Fig. 43, 45. 



