The presence of certain kinds of monsters in the uterus can be diagnosed before labor, but double monsters are mistaken for ordinary twins. A woman who has given birth to a monster is likely to have subsequent monstrous fetuses. Where the intrauterine existence of a single monster is suspected the X-ray will at times clear up the diagnosis. Women gravid with monsters commonly abort early in pregnancy, but even united twins may go on to term. Those monsters that offer an obstacle to delivery by the abnormal bulk of one or the other end are mostly twins joined above or below the navel; those joined at the middle are easier of delivery. Monsters that are joined at the pelves are commonly in a straight line, and may not be difficult to deliver. Most double monsters cannot be delivered alive except by cesarean section, and the fact that the content of the uterus is monstrous is, as a rule, not diagnosed until it is impossible to attempt cesarean section without killing the mother through infection. In such a condition the double monster would, in the ordinary medical practice, be delivered by craniotomy, exenteration, cleidotomy, or the like operation. The _Rituale Romanum Pauli V_[59] gives the following directions for the baptizing of human terata: "18. In monstris vero baptizandis, si casus eveniat, magna cautio, adhibenda est, de quo si opus fuerit, ordinarius loci, vel alii periti consulantur, nisi mortis periculum immineat. "19. Monstrum, quod humanam speciem non praeseferat baptizari non debet; de quo si dubium fuerit, baptizatur sub hac conditione; _Si tu es homo ego te baptizo_, etc. "20. Illud vero, de quo dubium est, una ne, aut plures sint personae non baptizetur, donee id discernatur: discerni autem potest si habeat unum vel plura capita, unum vel plura pectora; tune enim totidem erunt corda et animae, hominesque distincti, et eo casu singuli seorsim sunt baptizandi, unicuique dicendo: _Ego te baptizo_, etc. Si vero periculum mortis immineat, tempusque non suppetat, ut singuli separatim baptizentur, poterit minister singulorum capitibus aquam infundens omnes simul baptizari, dicendo: _Ego vos baptizo in nomine Patris, et Filii, et Spiritus Sancti_. Quam tamen formam in iis solum, et in aliis similibus mortis periculis, ad plures simul baptizandos, et ubi tempus non patitur, ut singuli separatim baptizentur, aliis nunquam, licet adhibere. "21. Quando vero non est certum in monstro duas esse personas, ut quia duo capita et duo pectora non habet distincta; tune debet primus unus absolute baptizari, et postea alter sub conditione, hoc modo: _Si non es baptizatus, ego te baptizo in nomine Patris, et Filii, et Spiritus Sancti_." [59] Tit. ii, cap. 1, nn. 18, 19, 20, 21.