THE OSSEOUS SYSTEM. 287 



concentric layers, often enclose merely a minute cavity, with a shrunken 

 nucleus; and besides these, smaller cells frequently in process of dissolu- 

 tion, isolated or aggregated together ; and, lastly, an indistinctly fibrous 

 or granular matrix, not unfrequently observed in a state of disintegra- 

 tion, and a considerable quantity of fluid contained in larger or smaller 

 areolar spaces in it. The more central portions of this fibrous substance 

 gradually pass into a thin, hard, yellowish lamella of true cartilage, with 

 thickened cells, not unfrequently beset with calcareous particles, which 

 adheres to the bone not unlike an articular cartilage, though less firmly. 

 More externally we find a cartilaginous substance, in the form of isola- 

 ted, minute, discoid plates or particles, which appear to be in more im- 

 mediate connection with the fibro-cartilaginous portions, and between 

 these a connective tissue, with scattered cartilage-cells, as in the inser- 

 tions of the tendons into the bones {vide § 81). The more exterior por- 

 tions of the surfaces of the bodies of the vertebrae, corresponding to these 

 parts of the discoid-ligaments, are, in contradistinction to the more in- 

 ternal portions, as it were porous, after the removal of the ligamentous 

 layer ; the medullary cavities or cancelli then being exposed. The 

 pores or cancelli are closed only by the cartilaginous substance of the 

 disc, whilst the fibrous tissue, with its vertical fibres, is firmly connected 

 with the interspaces between them. 



Between the sacrum and coccyx, and the individual coccygeal verte- 

 brae, are interposed the so-called fahe intervertebral ligaments, consist- 

 ing of a more uniform fibrous substance, without any gelatinous nucleus. 

 The separate bones of the sacrum, at an early period, have true inter- 

 vertebral ligaments between them, which afterwards become ossified 

 from without to within, but in such a way, nevertheless, that even in the 

 adult, traces of the ligament may still be perceived in the centre. With 

 respect to the nature of the fibres of the intervertebral ligaments, Bon- 

 ders is inclined, especially from the consideration of their chemical re- 

 lations, to regard almost all of them, not as connective tissue, but as 

 analogous to the matrix of true cartilage, as is also H. Meyer (p. 300, 

 et seq., and p. 310). This opinion may be correct, as regards the cen- 

 tral, nuclear portion, and the fibro-cartilaginous laminse of the outer 

 portions, but hardly so with respect to the purely fibrous parts of the 

 latter. I believe, moreover, that it is not by chemistry, but by the 

 study of the development of these tissues, that the question will be 

 solved, because, although manifest, visible distinctions exist between the 

 fibrils of connective tissue developed from cells, and the fibrous inter- 

 cellular substance, viewed from a genetic point of view, chemistry pro- 

 bably is not in a condition to distinguish one from the other.* The in- 



* [In onr note on the connective tissue, we have already expressed the views we enter- 

 tain of the homologies of tlie elements of cartilage and connective tissue ; and we need 

 merely add that we know of no locality in which the transition of the matrix of cartilage 



