A wonderful case of permission foetu in foetu

In 1859 (? Is it a typo?) The author had to accept a baby, normally built with the exception of the following rare anomaly: the baby was born as if sitting astride a ball. Anus is missing; the sac, formed by the continuation of the fetal skin, occupies the buttocks and the back of the thighs to the scrotum and goes down to the middle of the legs. The skin that forms the membrane of this sac is of normal thickness and bluish-reddish color, depending on the bloody-serum contents of the bag and on the abundantly developed veins.