Pignot speaks of one twin two months before the other.

De Bosch speaks of a delay of seventeen days; and there were 2 cases on record in France in the last century, one of which was delayed ten days, and the other showed an interval of seven weeks between the delivery of the twins.

There is an old case on record in which there was an interval of six weeks between deliveries; Jansen gives an account of three births in ten months; Pinart mentions a case with an interval of ten days; Thilenius, one of thirteen days; and Ephemerides, one of one week.

Wildberg describes a case in which one twin was born two months after the other, and there was no secretion of milk until after the second birth.

A full description of Wildberg's case is given in another journal in brief, as follows: A woman, eighteen months married, was in labor in the eighth month of pregnancy.