Concerning the solutions of continuity which are described under the name of fractures, Depaul believes them to be of two kinds: the one, the true, due to external violence, to exaggerated muscular contractions, or to an essential weakening of the tissue, which lies at the seat of the trouble; and the other, llte false, those which coincide with the supposed intra-uterine rachitis.
Even as the curvature may be explained by an unequal development of the different parts of the same bone, so may the solutions of continu ity result from the fact that calcareous deposits are not made in one or more points of the shaft7 hence it is not a fracture which occurs, but an absence of ossification. It is of no account that there has been noted in many observations, in that of Chaussier in particular, the existence in the course of some of the long bones of certain enlargements, which have been cited as proof of fractures which have united, for there is nothing to show that there is true callus. A limited prominence of bony tissue is all that exists, and it is not harder to understand this superabundance of the calcareous material than the diminution, the absence or irregular ity of its deposit; and, according to Depaul, all these alterations of the bony tissue are of the same nature, and due to the anomalies of ossifica tion. The health of the mother has nothing to do with their development. In no case has scrofula, ra,chitis or syphilis been found. In many in
stances, the disease has occurred in twin pregnancies, which fact is prob ably connected with the development of the rickets.
As opposed to these ideas Spiegelberg says that histological examina tion proved that the process is identical in intra-uterine and extra-uterine rachitis.
Winckler makes two subdivisions: rachitis micromelica and annular ra.chitis. The first is eminently intra-uterine; the second, beginning, possibly, in the last months of pregnancy, passes into the intra-uterine phases of rickets. Willer has described a special alteration in the bones, characterized by disease of the primitive cartilages. Of all the diseases of the bones, that affecting the inuer surface of the skull is the rarest Spiegelberg once found a gumma. Wegner detected lesions of the bony canaliculi. In general, the changes in the bones are most marked in the end of the femur, then in the lower extremity of the tibia, and in the radius and ulna; later in the upper extremity of the humerus and of the radius, and lastly in the lower extremity of the humerus. This alteration is usually due to syphilis of the father. In addition to osteo-chondritis, Wegner has noticed alterations in the marrow of the canaliculi, sometimes diffuse, and sometimes in isolated patches. The medullary tissue is red dish, and under the microscope is found to be in a state of fatty degener ation, especially of the medullary cells and the walls of the vessels.