=Bones.=--Our knowledge of the minute pathology of the bones is far more complete and detailed than that of any other structure. This was to be expected in view of the fact that this is the only tissue in which the lesions are diagnostic. In considering the microscopic pathology it must be remembered that all the bones are rarely affected by scurvy, and that those that are involved show the scorbutic changes to a varying degree. One of the peculiarities of the lesion is that it involves the end of the diaphysis or rather the junction of the diaphysis and the cartilage. The bones most apt to show typical changes are the ribs; we shall therefore describe a section made through a costochondral junction. The costochondral junction is generally swollen, somewhat beaded, and when cut longitudinally shows on gross examination a transverse yellowish bar, corresponding to the area of disorganization which will be described below. Under the microscope the line of juncture is not sharp and straight as is normally the case, but presents a wavy or irregular contour, the cartilage jutting into the bony end of the rib, instead of abutting in neat apposition to it. The bone is hollowed out and irregularly concave, whereas the cartilage presents a convex appearance. At the site of the junction is the _Truemmerfeld area_, where the normal tissue is splintered and fragmented. Everything in a state of disorder--trabeculæ of bone of various shapes and sizes lie scattered about, the cells irregularly arranged and much distorted, signs of recent hemorrhage, unrecognizable detritus. The picture is that of weakened bone having been crushed by the pressure of the more compact cartilage. Higher magnification shows that there are few osteoblasts (generally associated with the deeper fragments of bone), a varying number of intact red cells, according to the occurrence of hemorrhage, and occasional spindle- and star-shaped connective-tissue cells. Covering this mass of detritus there is frequently, as Aschoff and Koch have emphasized, more or less protective fibrin which has undergone some hyaline or connective-tissue organization. The cartilage is also not normal. Its cells do not present an orderly arrangement, the proliferating columns having disappeared in the central convex portion, and being present to a varying extent near the periosteal borders. If we judge from sections of early scurvy in guinea-pigs, this disturbance of the columnar formation of the proliferating cartilage is one of the early signs of scurvy, and is associated with an unevenness and irregularity in shape and size of the bone trabeculæ. In young individuals, where cartilage activity is great, these changes are most marked and the entire zone of active cells may be somewhat widened.