Hollerus has seen a woman who had two nipples on the same breast which gave milk with the same regularity and the same abundance as the single nipple.

The Ephemerides contains a description of a triple nipple.

Barth describes "mamma erratica" on the face in front of the right ear which enlarged during menstruation.
Cases of deficiency of the nipples have been reported by the Ephemerides, Lentilius, Severinus, and Werckardus.
Cases of functional male mammae will be discussed in Chapter IX.
Complete absence of the hymen is very rare, if we may accept the statements of Devilliers, Tardieu, and Brouardel, as they have never seen an example in the numerous young girls they have examined from a medico-legal point of view.
Duplication or biperforation of the hymen is also a very rare anomaly of this membrane.

In this instance the hymen generally presents two lateral orifices, more or less irregular and separated by a membranous band, which gives the appearance of duplicity.

Roze reported from Strasburg in 1866 a case of this kind, and Delens has observed two examples of biperforate hymen, which show very well that this disposition of the membrane is due to a vice of conformation.