Under the more favourable conditions an attempt may be made at the extirpation of the growth. The operation should be rendered as bloodless as possible, for which purpose it is essential that the scalp-tourniquet should be applied as a preliminary measure. A scalp-flap is then framed, suited to requirements, and allowing of free exposure of the tumour and surrounding healthy tissues. The skull is then trephined to one side of the growth, and the disk removed. The dura is separated from the overlying bone, and by the circumferential application of de Vilbiss or other craniectomy forceps the central mass is isolated and removed. During these manipulations free hæmorrhage may be experienced from the numerous dilated diploic veins. For the arrest of this the surgeon should have ready to hand, ivory pegs, bone-wax, and other aids for the control of hæmorrhage (see Chapter II). The scalp-flap is then replaced. [Illustration: FIG. 96. AN INTRINSIC SARCOMA OF THE SKULL.] The gap in the bone may be covered in, at a later date, if the patient’s condition is favourable. The operation may be a formidable one, but records are to hand of 35 cases in which radical measures were adopted. Ten cases died from the operation, 13 were well for periods varying from six months to six years; and recurrence took place soon after the operation in 21 cases. =Chloromata.= Chloroma, a peculiar type of sarcoma characterized by the pale green hue of the tissues, usually develops in the young. The cells are small and round, the pigment distributed in and around the cell elements. The colour, said to be dependent on the presence of a pigmented fat, is most intense immediately after the removal of the tumour, fading rapidly on exposure to light. The tumour develops from the periosteum of bones, more especially from those which enter into the formation of the orbit and base of skull. In fact, nearly all the cases reported have originated from the temporal and orbital regions. Great rapidity of growth and early dissemination throughout the viscera are conspicuous features--no organ of the body can be said to be exempt from metastatic deposits. The meninges and brain are early involved by direct extension. Proptosis, as the result of cavernous sinus thrombosis and orbital invasion, is a prominent and early symptom. Death results within six months. No treatment, surgical or otherwise, is of any avail.