404 THE ANATOMY OF THE HORSE 



their synovial capsule is continuous, and the two oblong ybss«j on the sternuin 

 unite one with the other. It must be fui'ther noticed that this articulation 

 frequently occurs on the cariniform cartilage, which is anterior to the first 

 bone of the sternum. 



As regards the two posterior sternal cartilages, they are in close apposition 

 one with the other, and fit into one common fossa situated on the posterior 

 bone of the sternum, and with it form one synovial joint. 



A thin fasciculus of fibres connects the cartilages of the 8th and 9th 

 ribs to the ensiform or xiphoid cartilage, called the chonclro-.ciphoid 

 ligament. 



A similar fasciculus to the foregoing connects the cariniform and xiphoid 

 cartilages together — the carino-xiphoid ligament. 



The asternal or false cartilages are united one to the other by a yellow 

 elastic ligament, which extends from the fore extremity of each to the 

 posterior border of the preceding cartilage. 



Ox THE SUPERIOR AXD INFERIOR SURFACES of the sternum, ligamentous 

 fibres may be observed running longitudinally, called the superior and 

 inferior sternal ligaments. The longitudinal fibres are mixed with those 

 radiating from the costal cartilages, especially inferiorly, where they blend 

 with aponeuroses of the pectoral muscles. 



PECULIARITIES IN THE ARTICULATIONS OF 

 THE LUMBAR VERTEBRAE 



The four anterior lumbar vertebra have nothing remax-kable about 

 them, but the fifth differs in having on the posterior part of each trans- 

 verse process an articular surface furnished with a synovial capsule, for 

 uniting it with the sixth. This last has also four articulatory surfaces on 

 its transverse processes — two anteriorly, which unite with the correspond- 

 ing ones on the fifth vertebra just described, and two posteriorly, which are 

 similarly furnished with synovial capsules, and which unite it with the 

 sacrum. 



THE LUMBRO-SACRAL ARTICULATION AND 

 SACRAL LIGAMENTS 



TuE FIBRO-CARTILAGE intervening between the last lumbar vertebra 

 and the sacrum is unusually thick, and the joint is protected also ex- 

 ternally by some strong longitudinal fibres passing from bone to bone. Tlio 

 last lumbar vertebra joins the sacrum not only by its body and articular 

 processes (which latter are oval, with their long diameter from side to 

 side), but also by two oval and slightly concave articular surfaces, which 

 articulate with corresponding faces on the last lumbar vertebra already 

 alluded to. 



Besides the articulations between the lumbar vertebrise and the sacrum, 

 there are also ligaments between the spines of the sacrum itself, which are 

 no longer of much use after the separate bones of which it is composed are 

 united by ossification. 



