=3. The third phase= is characterised by fractures, and it is this peculiarity of the disease which has procured for it the names of fragilitas ossium, and osteoclastia. These fractures may affect any portion of the skeleton. Animals so suffering sometimes break a leg whilst trotting or the pelvis in simply jumping over a ditch; a collision with a fixed object like the jamb of the stable door, or a fall on the ground, may result in the fracture of one or several ribs. [Illustration: $1] Such shocks would be of no importance to a healthy animal, but to one suffering from osseous cachexia, any violence, or even the slightest muscular effort may be followed by fracture of the gravest character, involving even the vertebral column. In cows the pelvis, femur, and tibia are most frequently injured. In horses, particularly in riding horses, fractures are commonest in the region of the forearm, cannon bone, and anterior phalanges. So extremely fragile are the bones at this stage that the horse represented herewith broke twelve ribs at one time by simply falling on its side. It is interesting to note that such fractures are never accompanied by any extensive bleeding. They have little tendency to repair, no real callus formation occurs, and on post-mortem examination one often finds the ends unconnected by temporary callus, worn, and rounded by reciprocal friction. At this stage but under other circumstances, the animals show great reluctance to rise, remaining down for twelve to twenty-four hours without shifting their position. If forced to get up, they stand as though fixed in one position, the respiration and circulation become rapid, and they soon grow tired and fall. =4. The fourth phase=, or period of osteomalacia, _i.e._ softening of the bones, is also the last. It is rarely seen in large animals like horses and oxen, because accidents so often accompany the preceding stages and necessitate slaughter; but it is common in goats and pigs. In this phase the bones become elastic, soft and depressible, yielding to the pressure of the operator’s fingers. [Illustration: $1] The flat bones are particularly liable to this change, which is common to domesticated animals. The bones of the head are the first to suffer; later those of the pelvis. The lower jaw becomes swollen, particularly about the centre of the branches which may attain three, four, or five times, their normal thickness. The depression in the submaxillary space disappears. The upper jaw undergoes similar changes, becoming deformed and thickened until the cavities of the sinuses and the hollow appearance of the palate are lost, while the face is so changed that it cannot be recognised as that of a horse, goat, etc. The molar teeth are almost buried, their tables alone being visible at the bottom of a depression, the edges of which rise above the neighbouring parts (pig).