Notice of several cases of malformation of the external ear, and of experiments on the state of hearing in such persons, / by Allen Thomson ... Together with an account of the dissection of a similar case of malformation / by Joseph Toynbee.

  • Thomson, Allen, 1809-1884.
Date:
1847
Catalogue details

Licence: Public Domain Mark

Credit: Notice of several cases of malformation of the external ear, and of experiments on the state of hearing in such persons, / by Allen Thomson ... Together with an account of the dissection of a similar case of malformation / by Joseph Toynbee. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    DISSECTION OF A CASE OF MALFORMATION IN THE EARS OF A CHILD By JOSEPH TOA^^BEE, F.R.S., SENIOR 8UBOEON TO THE ST OEOBOE’s AND 8T JAMES* DISPEN8ABT. (Read before the Pathological Society of London, January 18, 1847 ) The specimen which forms the subject of the present commu- nication was brought before the Pathological Society, by Dr Lloyd, physician to the Aldersgate Dispensary, and at his request I con- ducted the dissection. The subject of dissection, was a child bom at the seventh month of pregnancy, who died immediately after its birth from hemorr- hage taking ])lace from the umbilical cord, which was severed close to the umbilicus by an ignorant midwife. The external ear consists of a fold of integuments having much the same shape and size as the natural lobe, but it is directed for- wards, so that the concave surface which usually looks outwards, is directly applied to the surface of the head, and conceals the tragus which is rather smaller than natural. There are two orifices on the upper part of the anterior surface of this appendage and one at its posterior part; these are the openings of mucous follicles. The meatus externally is entirely absent, a slight depression in the integuments is the only indication of its usual position. Upon dissection no membrana tympani was discovered, but in its place is a flat surface of bone which presents two fissures, one very narrow and having a direction forwards, and a second three or four lines in length, and from half to three quarters of a line in breadth, which commences at the anterior and inferior part of the other fissure, and has a direction downwards and slightly backwards. This fissure is covered by a membrane. The whole of the auditory ring is absent, so that the mastoid and squamous portions of the temporal bone are only parted by these fissures, the lower of which represents the Glasserian fissure, and the external auditory meatus united into one ; and as Professor Allen Thomson has observed in his valuable paper on this subject for the Edinburgh Monthly Journal, the whole of the fossa parotidea is absent.* * An examination of the adult skull will show how an absence of the exter- nal auditory meatus will produce the relations here described.