_Clinical Features._--The _meningocele_ is commonest in the occipital region, where it escapes through a cleft in the bone between the foramen magnum and the occipital protuberance (Fig. 197). It forms a tense, smooth, translucent globular swelling, which may be sessile or pedunculated, and is usually covered by thin, smooth skin in which the vessels are dilated and nævoid. The tumour does not pulsate, but increases in size and tension when the child cries or coughs. It may be diminished in size or even made to disappear by pressure, and so permit of the opening in the bone being felt. This manipulation, however, may be followed by slowing of the pulse, vomiting, loss of consciousness, or convulsions. [Illustration: FIG. 197.--Occipital Meningocele. (From a photograph lent by Sir George T. Beatson.)] Small meningoceles may remain stationary for a long time, or may even undergo spontaneous cure. Those of larger size usually progress till they eventually burst, and death results from the escape of the cerebro-spinal fluid or from meningitis. Infection may also occur from eczema or from excoriation of the overlying skin. _Encephaloceles_ are much commoner than meningoceles, and usually occur in the frontal region, where they form broad-based, elastic, and pulsatile tumours, which vary greatly in size. The _hydrencephalocele_ is usually met with in the occipital region, and is generally so large and associated with such great cerebral deformity as to be inconsistent with life. It does not as a rule pulsate (Fig. 198). [Illustration: FIG. 198.--Frontal Hydrencephalocele. (From a photograph lent by Sir George T. Beatson.)] Cephaloceles have to be diagnosed from dermoid cysts, nævi (Fig. 199), cephal-hydrocele, and cephal-hæmatoma. Their recognition is seldom attended with difficulty. If the margins of the gap in the skull can be distinctly felt, or the gap in the bone can be shown by the X-rays, the diagnosis is greatly simplified. [Illustration: FIG. 199.--Nævus at Root of Nose, simulating Cephalocele. (From a photograph lent by Sir George T. Beatson.)] _Treatment._--Only small cephaloceles are amenable to surgical treatment; those that are large and contain brain substance are best left alone, being merely protected from irritation and infection. While the immediate effects of operation are, on the whole, satisfactory, the ultimate results are disappointing, as the essential cause of the intra-cranial pressure persists, and the child develops hydrocephalus. The method of tapping the sac and injecting iodine has nothing to recommend it.