Looking at the question from all points of view, it may be accepted that most cephaloceles contain either true brain-matter or the mixed epiblastic and mesoblastic elements described by Lyssenkow. The following case serves to illustrate some of these facts:[9]-- The child was 3 months old, and presented a tumour, the size of an orange, situated between the occipital protuberance and the nape of the neck. The mass was pedunculated, the stalk being about the size of a four-shilling piece in diameter. It was soft, translucent, irreducible, and swelled up on coughing. An attempt at removal was carried out, and, after incising the outermost layers, three ounces of cerebro-spinal fluid escaped. A second tumour was then found occupying the base of the swelling. This was also punctured, more fluid escaping. Both sacs were cut away and the wound sewn up. Death occurred on the third day, preceded by convulsions, retraction of the head and neck, and high fever. The autopsy showed that the fontanelles were widely open, the anterior measuring 4 inches from side to side and 2¹⁄₂ from before backwards. The bones of the vault were markedly thinned. In the subdural space there was a quantity of fluid, and the cerebral substance was soft and diffluent, the convolutions flattened, and the ventricles distended. There was a broad gap in the occipital bone, extending downwards into the foramen magnum, and in this situation the cerebellum had bulged backwards into the protruding mass. (See Fig. 22). For _differential diagnosis_, _see_ p. 57. _Treatment._ In considering the question of treatment, the late Professor von Bergmann[10] divided the cases into two groups:-- 1. _Inoperable cases._ When associated with premature synostosis and microcephaly. When associated with hydrocephalus or marked deformity. When the tumour is situated below the occipital protuberance. 2. _Operable cases._ Limited protrusions with none of the above defects and disadvantages.