twins, which is placed by
Taruffi with that of the ischiopagous twins in the group dicephalus
lecanopagus. Similar instances, which are well known to students of
teratology, are the Hungarian sisters (Helen and Judith), the North
Carolina twins (Millie and Christine), and the Bohemian twins (Rosalie
and Josepha Blazek). The interspace between the thoraces may, however,
have simply been the addition of the first artist who portrayed the
Maids (from imagination?); then it may be surmised that they were
ectopagous twins.

"Pygopagous twins are fetuses united together in the region of the
nates and having each its own pelvis. In the recorded cases the union
has been usually between the sacra and coccyges, and has been either
osseous or (more rarely) ligamentous. Sometimes the point of junction
was the middle line posteriorly, at other times it was rather a
posterolateral union; and it is probable that in the Biddenden Maids it
was of the latter kind; and it is likely, from the proposal made to
separate the sisters after the death of one, that it was ligamentous in
nature.

"If it be granted that the Biddenden Maids were pygopagous twins, a
study of the histories of other recorded cases of this monstrosity
serves to demonstrate many common characters. Thus, of the 8 cases
which Taruffi has collected, in 7 the twins were female; and if to
these we add the sisters Rosalie and Josepha Blazek and the Maids, we
have 10 cases, of which 9 were girls. Again, several of the pygopagous
twins, of whom there are scientific records, survived birth and lived
for a number of years, and thus resembled the Biddenden terata. Helen
and Judith, for instance, were twenty-three years old at death; and the
North Carolina twins, although born in 1851, are still alive. There is,
therefore, nothing inherently improbable in the statement that the
Biddenden Maids lived for thirty-four years. With regard also to the
truth of the record that the one Maid survived her sister for six
hours, there is confirmatory evidence from scientifically observed
instances, for Joly and Peyrat (Bull. de l'Acad. Med., iii., pp. 51 and
383, 1874) state that in the case seen by them the one infant lived ten
hours after the death of the other. It is impossible to make any
statement with regard to the internal structure of the Maids or to the
characters of their genital organs, for there is absolutely no
information forthcoming upon these points. It may simply be said, i