MONS TROSI TIES. <*21 



and the other in the posterior presentation, then we may bo certain that 

 they are not united. Heterologous parts do not unite. 



The diagnosis in the case of Monocephahan monstrosities is com- 

 paratively easy when the head presents. But much care and attention 

 are necessary in forming a diagnosis in such cases, and the examination 

 of the bodies should lead, if possible, to an exact notion of their condition. 



Extraction. 



In some cases, though they are very rare, extraction may be possible 

 by manipulation and judicious traction ; but as a rule, embryotomy, or 

 even the Cicsarian section, has to be practised. If it were possil)le to 

 separate the two individuals by excising the parts which unite them, 

 then birth would probably be as easy as with twins ; but it can rarely 

 be practicable, for the simple reason that the point of union is gener- 

 ally beyond reach : it is too extensive to be cut through, or the junction 

 is of an osseous character. Nevertheless, cases may occur in which 

 the knife and the obstetrical saw or bone forceps may be most effectively 

 employed in accomplisliing disunion. 



Wlien the monstrosity is in the anterior presentation, should it prove 

 to be double-headed, then it will be found advisable to remove one of 

 the heads as low down the neck as possible ; after this is done, removal 

 of two or more of the anterior limbs by subcutaneous section, will often 

 diminish the diameter of the body to such an extent that traction on 

 the head and x-emaining skin of the limbs will sometimes effect delivery. 

 If not, then eventration of the thorax and abdomen will be necessary. 

 When the two croups cannot be made to pass through the pelvis together, 

 it will be imperative to divide each across, as far back as possible, 

 extract the anterior halves, push the posterior into the uterus, turn 

 them, and deliver them as in the posterior presentation. Sometimes 

 excision of one or more of the hind limbs, in order to diminish the 

 volume of the double croup, will be necessary before the operation can 

 be completed. With Monocephalic monstrosities, of course the head 

 and neck are not interfered with, only the body and limbs requiring 

 attention. 



When the presentation is posterior, the procedure must be carried 

 out in a similar manner ; but in all cases the task is a long and 

 fatiguing one, and the tax upon the endurance and sensibility of the 

 mother is heavy indeed. 



('II.\PT1:R IV. 



Dystokia from Multiparity. 



At p. 164 allusion was made to the relative position of the young in 

 multiple pregnancy, and at p. 262 we described the manner in which 

 twin births take place. We need not again refer to these, but we must 

 notice those cases — rare, it is true — in which difficulties are encountered 

 from pathological conditions in twin parturition. As has been shown, 

 in ordinary cases one foetus occupies the body of the uterus, the other 

 one of the cornua, or both may be in thecornua ; and both may present 

 either anteriorly (Fig. 47), posteriorly, or one in the first and the other 

 in the second presentation (Fig. 66). One alone must pass through the 

 genital canal, then the other, as there is not space for both at once ; 



