362 THE HORSE. 
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 LUMBO-SACRAL ARTICULATION AND SACRAL 
LIGAMENTS. 
THE 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. The 
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. 
BrstDES THE ARTICULATIONS between the lumbar vertebre 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. 
THE COCCYGEAL JOINTS. 
THE SACRO-COCCYGEAL AND INTER-COCCYGEAL ARTICULATIONS are con- 
structed much after the same principle as the other vertebral articulations. 
The coccygeal bones, however, are only united together by their bodies. 
The anterior and posterior articulatory surfaces of each vertebra are both 
convex, and their inter-articular fibro-cartilage is hollow on both surfaces. 
As to ligaments, they are represented by bundles of longitudinal fibres 
spread on the surfaces of these bones, which they envelope in a common 
sheath. 
THE TEMPORO-MAXILLARY ARTICULATION. 
THE LOWER JAW articulates on each side by one of its condyles with 
the glenoid cavity of the temporal bone. Between them is placed an 
inter-articular fibro-cartilage, with one synovial membrane above and 
another below it. 
The articular surfaces above mentioned do not exactly fit one into the 
other. This, however, is corrected through the interposition of a fibro- 
cartilaginous disc between them. ‘This disc represents an irregular plate, 
flattened above and below, thicker in front than behind, moulded on each 
surface, which it separates, so that its superior face presents in front a 
concavity to receive the tubercle on the zygomatic process of the temporal 
bone, and a convexity behind, which is lodged in its glenoid cavity. As 
to its inferior face, it is indented by an oblong furrow, in which the 
condyle of the inferior maxillary bone is imbedded. 
These bones are united by a capsular ligament, covering a synovial 
capsule, and two lateral ligaments, one external and the other internal. 
A fibrous cover, a true capsular ligament, surrounds this articulation, and 
is attached by its edges to the articular surfaces which it unites, as well as 
to the borders of the inter-articular fibro-cartilage; thus forming two 
distinct, capsules, namely, one superiorly, and one inferiorly, which are 
lined internally by synovial membranes. The larger of the two, after 
lining the upper surface of the disc, is reflected upward to the glenoid 
