+Bunion.+ This is a bursal enlargement over the metatarsophalangeal articulation of the great toe, which is very frequently observed with hallux valgus, this being the most universal cause. The part is swollen and tender upon pressure, and if suppuration occurs the pain is severe, and cellulitis is apt to develop, involving the surrounding parts, or the joint may be involved, caries of the bones of the articulation resulting. +Treatment.+ If suppuration has not occurred, the part should be protected from pressure by a circular shield of felt or plaster; if suppuration has taken place, the part should be incised and drained, and if the joint is found diseased it should be curreted and dressed with an antiseptic dressing; if malposition of the toe exists, its position should be corrected by amputation of the head of the metatarsal. +Inflammation of Synovial and Serous Membranes.+ When the serous and synovial membranes are attacked by inflammation, the stage of congestion is accompanied by exudation of serum and fibrin from the surface, and the endothelial cells become swollen and detached in large numbers. The serous exudation may be sufficient to fill the entire cavity involved. There is a form of dry or fibrinous inflammation, without fluid exudate, in which the surface of the membrane loses its polish, becoming dry and red, and adhesions readily form wherever the surfaces are in contact. In suppurative inflammation, pus is produced by emigration, and also by the detached endothelial cells. If fibrin is present, false membranes form on the surface and the membrane itself appears to be greatly thickened. At a later stage the proliferating cells invade these layers of fibrin and they become organized into connective tissue, and new vessels develop on them. Their tendency, however, is to disappear after a time, and the membrane returns to its original condition, unless the inflammation has been very intense, in which case the new connective tissue becomes permanent. Chronic inflammation of these membranes is marked by general thickening of all the layers, the formation of dense connective tissue in the fibrinous membranes, strong adhesions, and sometimes complete obliteration of the cavities, their endothelial lining disappearing entirely. +SYNOVITIS+ Like other structures of the body the joints are subject to injury and disease and because of the nature and course of pathologic processes in them, one should bear in mind their anatomic construction. The expanded ends of the bones in the joints are covered with a thin layer of cartilage and are bound to each other by a dense capsule which is firmly attached to the bones at their necks, where it is closely connected with the periosteum. The joint cavity is lined (excepting where additional fibrocartilages are present) with a synovial sac which sometimes communicates with a bursa.