=The prognosis= is not grave, though the condition may prove troublesome, because the original injuries may be continued even during treatment and prevent recovery. [Illustration: $1] =Treatment.= Success rarely follows cold applications or blistering, which are only of value at the commencement. It is better to puncture the cavity aseptically, remove the fluid contents, and fire the growth in points. Free opening of the lowest portion of the swelling is followed by discharge of liquid, but almost inevitably by infection at a later stage, and by suppuration. Recovery certainly may occur, a slight thickening of the anterior surface of the knee remaining; but the process is often very prolonged. Some authors prefer to pass a seton or drain vertically through the swelling. The results are identical with those following free opening and drainage, suppuration being unavoidable. If the animal be sufficiently valuable to warrant surgical intervention, the entire hygroma, together with its indurated wall, may be excised. An elliptical fragment of skin is removed from the front of the swelling, and the whole mass separated by dissecting away or tearing through the connective tissue. Considerable care is necessary to avoid injuring the synovial sheaths of the extensor tendons. This treatment, which is only applicable in valuable animals, is completed by firmly suturing the lips of the wound, and applying an antiseptic surgical dressing or a plaster bandage similar to that used in operating on broken knees in horses.[1] The animal must be prevented from lying down until the wound has firmly united. Footnote 1: See Dollar’s “A Surgical Operating Table for the Horse.” (London: Gay and Bird.) HYGROMA OF THE HAUNCH. With the exception of hygroma of the knee, hygromas are commoner on hind than on front limbs. That of the haunch is limited to the external angle of the ilium. It follows violent falls or collisions with door posts, and results from laceration of the layers of subcutaneous connective tissue and separation of the skin from subjacent parts. The effusion is often of a sero-sanguinolent character. It is more frequent in animals occupying narrow or irregularly shaped stalls, the hygroma being developed through repeated collision of the angle of the haunch with the wall. Finally, it may follow prolonged decubitus. =Diagnosis= is easy, but the =prognosis= has a certain element of gravity, because, should suppuration occur, it may be succeeded by necrosis of the aponeurosis inserted into the external angle of the ilium. =Treatment= should first be directed to removing the cause. Of the various modes of intervention, the best probably consists in disinfecting the parts, puncturing the swelling, and injecting some irritant of an antiseptic character, or simply washing out the cavity. Iodine and carbolic solutions are most commonly employed. Firing is contra-indicated.