94. In as much as the organization of the os femoris, is nearly the same in its neck and in its body, it is difficult to conceive how the progress of nature can be different in fractures of these two parts; why the first, in being denied the power of healing or reunion should be, in this respect, distinguished from all other living parts of animals, which are particularly characterized by that power, when they have sustained a solution of continuity. Many practitioners, even at the present day, advocate this doctrine, which is built, one while, on the circumstance of the periosteum not being continued along the neck of the os femoris; another while, on a belief that the head of this bone cannot receive a sufficiency of nourishment for the work of consolidation, in consequence of being attached to the rest of the system, only by the round ligament, and again, on an opinion, that the synovial fluid, by wetting the divided surfaces, prevents their reunion. 95. But is the periosteum the only agent in the formation of callus? Modern experience has refuted this opinion, which, like many others, will therefore in a short time exist only in the history of our errors. Were it even true that the periosteum is here indispensably necessary, is not its place supplied by the fold of the capsule, which surrounds both the head and neck of the os femoris? Besides, why cannot callus be formed by that part which has had sufficient power to accomplish ossification, since it is universally acknowledged, that, in these two processes, the labour of nature is nearly the same. 96. The head of the bone, separated from the soft parts, and attached to the acetabulum by the round ligament, always receives through that ligament a sufficiency of nutriment to enable it to live in that cavity; for, there is no instance of its having suffered mortification in consequence of a fracture. Why, then, should it not partake of the properties of life, and particularly of the faculty of reunion when placed in regular apposition with the body of the bone?