=X-ray examination.= X-ray examination should always be carried out. More commonly the results are negative, the nature of the tumour seldom permitting sufficient shadow formation. Occasionally the firmer and denser tumours allow of a more definite result. When the tumour arises from the bone, or is so situated as to change the shape of the part with which it is in contact, valuable information will be obtained. For example, the hollowing out and general enlargement of the sella turcica in pituitary tumour formation. =Treatment.= _Indications for operation._ The indications for operation must be considered under two groups:-- Those for radical operation aiming at the removal of the tumour. Those for palliative operation aiming at the alleviation of symptoms. _For the radical operation._ According to Risien Russell,[46] the following are the main indications:-- (1) Cases in which the tumour can be accurately diagnosed. (2) Cases in which the tumour is situated in an accessible position. The more favourable sites are the surface of the cerebrum, the lateral lobe of the cerebellum, and the cerebello-pontine angle. (3) Cases in which there is reason to believe that the tumour is simple, and of such a nature that it can be removed from its bed. (4) Cases in which there is reason to believe that the removal of the tumour will not greatly imperil the patient’s life, and, furthermore, will not result secondarily in the development of fits, paralysis, aphasia, &c. _For the palliative operation._ The following are the main indications for operation:-- To prolong life. To alleviate the severe and persistent headache. To stop fits. To save the sight. And, in general, to benefit the patient by reducing the increased intracranial pressure, _even though it may be quite impossible to remove or even locate the tumour_.