"There is, however, one real difficulty in accepting the story handed down to us as authentic,--the nature of the teratologic phenomenon itself. All the records agree in stating that the Maids were joined together at the shoulders and hips, and the impression on the cakes and the pictures on the 'broadsides' show this peculiar mode of union, and represent the bodies as quite separate in the space between the above-named points. The Maids are shown with four feet and two arms, the right and left respectively, whilst the other arms (left and right) are fused together at the shoulder according to one illustration, and a little above the elbow according to another. Now, although it is not safe to say that such an anomaly is impossible, I do not know of any case of this peculiar mode of union; but it may be that, as Prof. A. R. Simpson has suggested, the Maids had four separate arms, and were in the habit of going about with their contiguous arms round each other's necks, and that this gave rise to the notion that these limbs were united. If this be so, then the teratologic difficulty is removed, for the case becomes perfectly comparable with the well-known but rare type of double terata known as the pygopagous 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.