THE SPINE. 25 



the longest spinous processes are not co-ossified with the shaft. All of 

 them, on their anterior and posterior faces, are roughened at the insertion 

 of the inter-spinal ligament. 



The transverse processes are very thick in the first seven dorsal Transverse 



Processes. 



vertebrae, more prominent than in the others, and rough for muscular 



attachment : the extremities of all of them have a rough surface. 



The articulating processes are not prominent in the sixteen anterior Articulat- 

 ing 

 vertebrae, but. become so in the posterior on their anterior surface, the processes. 



posterior surface not being so ; their surfaces generally affect the horizontal 

 direction. The bodies (Plate XXII. Figs. 1, 2,. 3) have mostly a rounded 

 form, but the last approximates to an oval; they are of about the same 

 size in the different dorsal vertebrae. Their anterior and posterior surfaces 

 are smooth, as is also the superior or medullary surface; the inferior is 

 somewhat irregular, more flattened in the superior than in the inferior 

 vertebrae, the last having this surface a little excavated anteriorly. The 

 thirteen superior have a double articulating costal surface on each side, 

 near the superior edge of the body (Plate XXII. Fig. 4). The first articu- 

 lating surface is two inches and a half long, and two inches across. 



Another surface for the tubercle of the rib is seen on the inferior face 

 of the transverse processes of the thirteen superior bones. The medullary 

 canal is of a triangular form in the uppermost dorsal vertebrae, and 

 measures four inches on each side ; inferiorly, it is flattened or elongated 

 transversely. 



Lumbar Vertebrae. — These are three in number (Plate XXIII. Fig. 3). Lumbar 



Vertebrae. 



Their spinous processes are short and oblique ; in length they are the same 

 with that of the last dorsal. The transverse processes are very remarkable, 

 particularly that of the first lumbar. This vertebra, measured across the 



4 



