[33] The beading may have the usual, rounded, smooth, knobby character. There may be, however, what one might term "angular beading," the junction taking on a step-like form, as if the abutting ends of the cartilage and the bone were of unequal size and not well fitted to each other. The cartilage overtops the bone, so that on palpating the joint there is a precipitous fall as we run the finger outward from the surface of the cartilage, or a sudden elevation on palpating the rib from without inward toward the sternum. This beading of the ribs, which involves mainly the middle tier, was described by Holst and Froelich in their classic report of guinea-pig scurvy, and has been noted by all subsequent investigators in this field. It has usually been called "rhachitic" or "pseudo-rhachitic" in spite of the fact that this junction is the site of typical scorbutic microscopic lesions. Hart and Lessing refer to the "rhachitic rosary" in monkeys, likewise not realizing that it is the product of scurvy. The subperiosteal hemorrhage has long been recognized as a lesion characteristic of scurvy.[34] It occurs exceptionally in the upper extremities, and most commonly at the lower end of the femur; it may, however, involve almost any of the bones, and has been described in connection with the scapula, cranial vault, orbital plate of the frontal bone, ribs, etc. It varies greatly in its size, being confined to a small area or extending a long distance on the shaft of the bone. It rarely is as large as one would expect from external appearance, as much of the swelling is due to edema and hemorrhage into the soft parts. The periosteum rarely becomes separated at the line of junction of the epiphysis and diaphysis. The underlying blood coagulates rapidly, and the periosteum begins to calcify within a few weeks, as shown by the X-ray. [34] There seems to be some misconception as to the pathogenesis of the subperiosteal hemorrhage in scurvy. In most reports this lesion is described as if it resulted from a hemorrhage burrowing its way beneath the periosteum and raising it from the subjacent bone. In point of fact, such an event is impossible, as will be fully realized when one experiences the great difficulty in separating periosteum from normal bone. Scurvy involves a periosteum which is not normal; it is insecurely attached to the shaft of the bone, so that it is readily stripped off by hemorrhage.