The identical twin siblings wrote and starred in the tale of conjoined twins. They performed the latter whilst dressed to resemble conjoined twins. Two contradicting theories exist to explain the origins of conjoined twins. Dicephalic twins represent about 11 percent of all conjoined twins. The exact nature of how conjoined twins develop inutero remains unclear. She is the mother of former conjoined twins Louis and Lucien. In very rare cases, there may be conjoined twins, possibly impairing function of internal organs. It is the only book about conjoined twins written by a parent of conjoined twins. The next case of separating conjoined twins would not occur until 1689 in Germany. Morty informs the twins that word has leaked about Walt and Bob being conjoined. If the split occurs later than this time period, the twins risk being conjoined. Each twin manages one side of their conjoined body. The two are conjoined at the sinus tubercle. Individual letters are processed serially when spatially conjoined with another letter. To study the tumors, two adult female rats were conjoined.