Most children so affected are either still born or live but a very short time; to this, however, there are exceptions; one has already been mentioned, another has been related on the same authority,* and Guyenot brought before the Royal Academy of Surgery in 1774, a man of thirty-three years of age, with ence phalocele in the forehead, who had never ex perienced any disturbance of his intellectual faculties. Lallemand attempted to remove a tumour from the occipital region of a young woman of twenty-three, under the idea that it was a wen; but unfortunately, on attempting to operate, he found that it was an encephalo cele; inflammation ensued, and the patient died.
Spina bifida.—An affection in many respects analogous to that just described to which the foetus is liable, is that which has received the name of spina bifida, and consists of a tumour situated on some part of the spinal column, most frequently over the lumbar vertebrae, but it may be found at any point along the whole length of that column. The writer lately saw a case of it in which the tumour was situated so high on the cervical vertebrae, that it was diffi cult to determine whether it arose there, or from the base of the occipital bone. A similar case is recorded by Dr. Collins, in which a child was born with a tumour projecting from the back of the head nearly as large as the head itself; it burst, and the child died in ten hours: " The tumour to a considerable extent was covered with hair, the remainder being bare skin of a thin texture, with a blueish tinge ; with the exception of one spot the size of a shilling, which had almost the appearance of serous membrane.
" The ventricles of the brain were much dila ted and communicated freely with the sac. The membranes were extremely vascular, and the whole contents of the cranium in a dark con gested state. The opening through which the tumour had formed was about three-eighths of an inch in diameter, and half an inch behind the foramen magnum. The bones of the head generally were very imperfect as to ossifi cat The most unusual form of it is that in which the tumour appears at the very extremity of the sacrum, where it joins the coccyx. Ruysch, however, met with an instance of the kind, and Genga with another, in which there was also hydrocephalus, the fluid of which was eva cuated by opening the tumour on the spine.: A case occurred not long since in this city, under the observation of Dr. Dlurpliy, in which at the time of the birth of the child, which presented the breech, a membranous bag protruded before it, and was supposed at the moment to be the membranes of the ovum, but it was found to be the covering of a spina bifida tumour, over which the integuments were deficient : it was of considerable size, nearly equalling that of the child's head, and sprung from the very lowest point of the sacrum, as represented in the subjoined sketch :— In another instance, for the observation of which the writer is also indebted to Dr. Mur
phy, the tumour occupied the whole length of the sacrum, and was conjoined with diaphrag matic hernia. In some rare instances there have been more than one tumour : in size these tumours vary from the volume of a small nut to that of a child's head at birth ; and in their form there is also considerable variety, some being very exactly globular, while others are of the long oval, some pyriform with the tapering pedicle next the spine, and others broader in that situation than externally, and so rather representing the form of a cone. As a general description of the affection, its pathological anatomy is this : there is a deficiency in the posterior arch of one or more vertebra?, arising either from imperfect development of these bones, or their division ; through the opening thus caused, protrudes a sac consisting of the in vesting membrane of the spinal which sae is in general covered externally by the common integuments, which are sometimes in a healthy state, but more frequently diseased, being sometimes extremely attenuated, either wholly or partially and sometimes in a state of ulceration, or approaching to a state of gangrene; occasionally the integuments are altogether ab sent, and the membranes form the covering of the tumour ; the contents are a fluid of various characters in different cases ; appearing some times bloody, puriforrn, and otherwise con taminatetl, but when presenting its more natural serous condition, it is found, like that of hy drocephalus, to contain a smaller proportion of albumen than the fluid of other dropsies. Sometimes the fluid contained in the tumour can be made, merely by pressure on the latter, to retreat and pass along the spinal canal into the ventricles of the brain, producing the sym ptoms of cerebral compression ; and in such cases also, as in encephalocele, efforts, as of crying, coughing, &e. produce an immediate increase in the size of the tumour : and in the case mentioned by Morgagni, the enlargement of the head from hydrocephalus was diminished, when the spina bifida tumour was opened and its contents allowed to flow out..