1-78 OSSEOUS SYSTEM. [sect. 94. 



but are connected throughout the entire thickness of a yellow 

 ligament, there are found lax undulating fasciculi of connective 

 tissue in small proportion. 3. By Cartilage, Synchondrosis. 

 This mode of connection is effected by cartilage, either alone or 

 along with fibrocartilaginous and fibrous masses. The former 

 occurs, in the adult, only in the ribs, of which, however, only 

 the first is, properly speaking, connected to the sternum by a 

 true synchondrosis; the remaining true ribs being connected, at 

 their anterior extremities, by moveable articulations with the 

 sternum, and the false ribs being partly articulated with each 

 other, and partly ending quite free. The costal cartilages consist 

 of the ordinary cartilage-substance, but exhibit, in certain 

 places, a fibrous matrix, and for the most part cartilage-cells con- 

 taining fat. In the symphysis ossium pubis, the synchondrosis 

 sacro-lliaca, and the junctions of the bodies of the vertebrae, there 

 exists, immediately upon the bone, a layer of true cartilage, which, 

 in the two former localities, is connected with that of the opposite 

 side immediately, but in the latter by means of a fibro-cartilaginous 

 tissue, which, in the middle, forms a soft nucleus. They are sur- 

 rounded externally by concentric layers of fibro-cartilaginous and 

 fibrous substances. In the interior of these connecting substances, 

 there frequently exists, in the two former instances, a narrow ca- 

 vity, so that both, but more especially the sacro-iliac synchon- 

 drosis, may be regarded as a kind of joint, 



The intervertebral ligaments are subject to various kinds of degeneration ; 

 they become ossified from their cartilaginous lamella? outwards, so that two 

 vertebra are often found anchylosed ; they become atrophied and brittle, and 

 break down, either in the central portion, or in other circumscribed spots 

 into a dirty pultaceous matter ; finally, although they have no vessels in the 

 normal condition, they seem to acquire them in a morbid condition ; at least, 

 effusions of blood are not unfrequently found in them in small spots near or 

 in connection with the bone. The costal cartilages are very frequently «!- 

 fed in old age : yet this ossification, as well as the fibrillation of their matrix, 

 is not be regarded as a normal process, to be ranked with ordinary ossifi- 

 cation. Their ossification is sometimes more limited, sometimes more 

 extended. In the former case, it often does not go beyond the incrustation 

 of the cartilage cells and matrix, which has become fibrous ; in the latter 

 (and frequently, too, in the former), the ossification is preceded by the for- 

 mation of hollow spaces, and of a marrow with vessels, in the cartilage, which 

 are partly connected with those of the perichondrium, partly with those of 

 the osseous part of the ribs. The osseous substance is similar to the normal 

 tissue, but almost always darker and less homogeneous, and its lacunae, which 

 often contain granular calcareous precipitates, are not so well developed. 

 Under the name cartilage-marrow, are understood the marrow-cells, fat-cells. 

 bundles of connective tissue and vessels, which appear in the place of the 



