As these nodules give rise to the same symptoms as other forms of cerebral tumour, and as their nature can be diagnosed only in exceptional cases, their clinical features and treatment are described with tumours of the brain. #Intra-cranial Syphilis.#--_Syphilitic meningitis_ is usually secondary to cario-necrosis of the bones of the vault or to a localised gumma of the brain. When primary, it usually affects the inter-peduncular region of the base, and takes the form of a diffuse gummatous infiltration of the membranes which gives rise to symptoms referable to the parts pressed upon, and especially paralysis of one or other of the cranial nerves. As in other intra-cranial syphilitic lesions, the symptoms show a variability in intensity which is characteristic. The diagnosis is made by the history, and the treatment is carried out on the same lines as in other syphilitic lesions. _Localised gummata_ are described with tumours of the brain. CEPHALOCELES The term "cephalocele" is applied to a protrusion of a portion of the cranial contents through a congenital deficiency in the bones of the skull. This malformation is believed to be due to an irregularity in development, whereby a portion of the primary cerebral vesicle remains outside the mesoblastic layer of the embryo. It is usually associated with adhesion of the membranes in the region of the fourth ventricle, and with internal hydrocephalus. Cephaloceles are covered by the scalp, and are most commonly met with in the occipital region and at the root of the nose; less frequently at the anterior inferior angle of the parietal bone, and in the line of the sagittal suture. Very rarely they occur at the base of the skull and project into the pharynx, the mouth, or the nose, where they are liable to be mistaken for polypi. Cephaloceles vary greatly in size, some being so small as almost to escape detection, while others are larger than a child's head. In many cases the condition is incompatible with life. Several varieties are recognised. They are known as (1) _meningocele_, which consists of a protrusion of a cul-de-sac of the arachno-pial membrane, containing cerebro-spinal fluid; (2) _encephalocele_, in which a portion of the brain is protruded in addition to the membranes; and (3) _hydrencephalocele_, in which the protruded portion of brain includes a part of one of the ventricles.