These phenomena are nearly analogous to those of the ossification of the extremities of the long bones, which the short bones resemble so much. After birth, the whole cartilaginous portion, is, if we may so say, invaded by the calcareous substance, which mixes with it, and there is finally only the articular cartilages left. There are bones, as the occipital and sphenoid, which partake of the character of the broad and short bones; their ossification is mixed, and follows the mode of one or the other, according to the part of the bone that we examine. II. _State of the Osseous System after its Growth._ The bones, having become completely ossified, continue to undergo different phenomena which anatomists have too much neglected. The general growth in height is terminated when ossification is complete; and it even appears that the term of these two is nearly the same; but that in breadth continues for a long time after; compare the small and slender body of a young man of eighteen years, with the stout and well proportioned one of a man of forty, and you will see the difference. The bones follow the general law; their nutrition is prolonged for their thickness, when that for their length ceases. It appears that then the vessels which penetrate by the foramina of the first and second order, do not contribute to this nutrition, which draws its materials from those of the third; now, as we know that these very superficial vessels are arrested in the external fibres of the bone, and do not penetrate within, we understand, 1st, how, the growth going on without, the bone increases in thickness; 2d, how this increase takes place especially on the compact texture, the proportional thickness of which is in the direct ratio of the age, as we may see by inspecting the different bones of the child, the adult and the old person. This external growth has made it believed that the periosteum contributes to it especially by the ossification of its layers; but we shall see in the article upon this membrane, what opinion should be entertained upon this subject. It is principally at this period in which the work of nutrition seems spread upon the osseous surface, that the different eminences, which are scattered over this surface, become more evident; then especially all the prominences of insertion become more prominent; there is in respect to these eminences a remarkable difference between the skeleton of a child and that of a full grown man. In the fœtus they hardly exist, as we see particularly by the different apophyses of the vertebræ, the spinous especially. As these eminences are generally the most distant parts from the primitive osseous centres, it appears that it is to this circumstance that must be attributed the slowness of their formation, since ossification always goes from points where it begins, to the most distant ones.