514 ANATOMY OF VERTEBRATES. 



dorsal^ toAvards which the rest of the dorso-lumbar series slightly 

 incline. 



The vertebro3 go on increasing in size to the fifth of the 

 lumbar series, — ^the diapophyses more especially, which recom- 

 mence in the first lumbar ; these processes are directed forward 

 and doAvnward, as well as outward, are truncate, Avith the anterior 

 angle a little produced ; that of the last lumbar is similar in shape 

 and direction, but is smaller than the two preceding. The ana- 

 pophysis overlaps the front margin of the following vertebra to 

 the fifth lumbar, in which it becomes too short ; it disappears in 

 the sixth. The metapophysis overhangs the back part of the 

 neural arch of the preceding vertebra. The neural spine de- 

 creases from the third to the last lumbar, where it has 3 lines 

 of length. The last two ribs join their own centiiim close to the 

 front intervertebral space ; the rest have the usual intervertebral 

 articulation of the head. The first rib is the shortest (9 lines) 

 and thickest ; the others increase in length to the ninth, and 

 then gradually shorten to the thirteenth, which is 1 inch 3 lines 

 in length. The tubercle and diapophysial articulation exist to 

 the eleventh rib ; the twelfth and thirteenth articulate only by 

 the head. The first cartilage articulates with the manubrium, 

 the second to the seventh inclusive with the joints of seven 

 sternebers, the eighth with the seventh, and the ninth to the joint 

 between the seventh and eighth sterneber. 



The bodies of the cervical vertebrae are broad, short, and 

 flattened below in the last five. The last three have no neural 

 spines: there are tubercular beginnings of these in the fourth 

 and third ; in the second it is 2 lines long, thick, and produced 

 anteriorly ; in the atlas it is as a small tubercle. The seventh 

 cervical has a simple slender diapophysis, 2 lines in length ; in 

 the sixth it coalesces with the tubercle of a short pleurapophysis, 

 also confluent by the head with the centrum, and projecting 

 outward, backward, and doAvnward, with an obtuse end. The 

 vertebral artery, in its forward course, enters the canal between 

 the pleur- and di-apophyses. The pleurapophysis simply com- 

 pletes that bony canal in the fifth cervical, making a short an- 

 gular projection outward and forward in the fifth, fourth, and 

 third cervicals. The low flat neural arch is narrowest in the fifth. 

 The shape and disposition of the zygapophyses give an imbricate 

 character to the union of those arches in the last six cervicals. 

 The body of the axis is carinate below ; that of the atlas has 

 the usual state of an ' odontoid process ; ' the hypapophysial bar 

 uniting with the neurapophysial pillars or crura of the atlas is 



