MR. BOLTON ON THE UNITED SIAMESE TWINS. 
179 
like all their other external parts, regularly formed ; but the youths are natu- 
rally modest, and evince a strong repugnance to any close investigation on this 
subject. 
The band of union is formed in the following manner. — At the lowest part of 
the sternum of each boy, the ensiform cartilage is bent upwards and forwards, 
meeting the other in the middle of the upper part of the band, where moveable 
joints exist, which admit of vertical as well as lateral motion ; each junction 
appearing to be connected by ligamentous structures. It is difficult to define 
precisely where the respective cartilages from each body meet, and whether a 
slip from one of the cartilages of the false ribs enters into the structure of these 
parts ; but it is certain that the ensiform cartilages have assumed an extended 
and altered figure. This cartilaginous portion occupies the upper region of 
the band. The outline of the band is convex above, and arched below. Under 
the cartilage, while they stand in their ordinary posture, are large hernial sacs 
opening into each abdomen, and into which, on coughing, congenital hernise 
are forced ; probably, in each boy formed by a portion of the transverse arch 
of the colon : generally, however, and under ordinary circumstances, these 
hernise are not apparent. Whether there is a communication between the two 
abdominal cavities, or a distinct peritoneal sac belonging to each hernia, is by 
no means obvious ; and this is a point of vital importance, if ever, by their 
mutual desire, a surgical separation should be contemplated. If, however, 
any such operation hereafter be strongly requested by both the youths, when 
arrived at years of discretion, and after they have been fully apprised of its 
danger, it will be essential that some preliminary steps be taken to provide 
against the exposure of either or both of the abdominal cavities. 
When these hernise protrude, their respective contents are pushed forwards 
as far as the middle of the band. The entire band is covered with common 
integument ; and when the boys face each other, its length at the upper edge 
is one inch and three quarters, and at the lower, not quite three inches. From 
above downwards, it is three inches and a quarter, and its greatest thickness is 
one inch and five-eighths. In the centre of the lower part of this band, which 
presents a thin edge, formed only by skin and cellular substance, there is the 
cicatrix of a single navel, showing where the umbilical cords or cord had 
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