Dicephalic parapagus twins Dicephalic parapagus twins Dicephalic parapagus \ dī-ˈsef-ə-lək \ is a rare form of partial twinning where there are two heads side by side on one torso. Infants conjoined this way are sometimes called "two-headed babies" in popular media. The condition is also called parapagus dicephalus. If carried to term, most dicephalic twins are stillborn, or die soon after birth. A small number are known to have survived to adulthood. The extent to which limbs and organs are duplicated varies from case to case. One head may be only partially developed (anencephalic), or both may be complete. In some cases, two
Tarzan and the Tarzan Twins it features Tarzan's first meeting with Doctor Karl von Harben, with whom he is already acquainted in "Empire". Because "Twins" is a children's book, however, it is customarily omitted from listings of the main Tarzan series. Thus "Tarzan, Lord of the Jungle" is generally considered the eleventh Tarzan book rather than "Twins". Two schoolboys, Dick and Doc, are cousins who resemble each other because their mothers are twins. As Dick is also related to Tarzan through his father, they become known as the Tarzan Twins. Invited to visit Tarzan's African estate, they become lost in the jungle and are imprisoned