4. All the degrees of duplication have been met with, from a fissure of the glans penis to the presence of two distinct penises inserted at some distance from each other in the inguinal regions. 5. The two penises are usually somewhat defective as regards prepuce, urethra, etc.; they may lie side by side, or more rarely may be situated anteroposteriorly; they may be equal in size, or less commonly one is distinctly larger than the other; and one or both may be perforate or imperforate. 6. The scrotum may be normal or split; the testicles, commonly two in number, may be normal or atrophic, descended or undescended; the prostate may be normal or imperfectly developed, as may also the vasa deferentia and vesiculae seminales. 7. The commonly associated defects are: More or less completely septate bladder, atresia ani, or more rarely double anus, double urethra, increased breadth of the bony pelvis with defect of the symphysis pubis, and possibly duplication of the lower end of the spine, and hernia of some of the abdominal contents into a perineal pouch. Much more rarely, duplication of the heart, lungs, stomach, and kidneys has been noted, and the lower limbs may be shorter than normal. CLASS XI.--Cases of fetus in fetu, those strange instances in which one might almost say that a man may be pregnant with his brother or sister, or in which an infant may carry its twin without the fact being apparent, will next be discussed. The older cases were cited as being only a repetition of the process by which Eve was born of Adam. Figure 63 represents an old engraving showing the birth of Eve. Bartholinus, the Ephemerides, Otto, Paullini, Schurig, and Plot speak of instances of fetus in fetu. Ruysch describes a tumor contained in the abdomen of a man which was composed of hair, molar teeth, and other evidences of a fetus. Huxham reported to the Royal Society in 1748 the history of a child which was born with a tumor near the anus larger than the whole body of the child; this tumor contained rudiments of an embryo. Young speaks of a fetus which lay encysted between the laminae of the transverse mesocolon, and Highmore published a report of a fetus in a cyst communicating with the duodenum. Dupuytren gives an example in a boy of thirteen, in whom was found a fetus. Gaetano-Nocito, cited by Philipeaux, has the history of a taken with a great pain in the right hypochondrium, and from which issued subsequently fetal bones and a mass of macerated embryo. His mother had had several double pregnancies, and from the length of the respective tibiae one of the fetuses seemed to be of two months' and the other of three months' intrauterine life. The man died five years after the abscess had burst spontaneously.