DYSTOKIA FROM MULTIPARITY. 429 



this cause always happens when the two foetuses are about the same 

 distance from the os uteri, and both present together at the pelvic inlet; 

 the uterine contractions carry them simultaneously into the opening, but 

 of course they cannot possibly pass through the canal at the same time ; 

 hence the difficulty in birth — a difficulty which varies according to the 

 relative situation of the two foetuses towards each other. 



The foetuses may be so situated that when the hand is introduced into 

 the vagina or os. it will either encounter the head of one foetus with the 

 fore limbs of the Qther ; four anterior or posterior limbs ; two hind and 

 two fore limbs (Fig. 105) ; two, four, or six feet ; a head and a tail, etc. 



The cause of this malposition is in all probability due to the relative 

 smallness of the twins, and the changes which occur in their situation 

 during birth ; and it will be apparent that the obstetrist must, in some 

 cases at least, find it difficult to distinguish between such presentations 

 of twins and some of the monstrosities or deformities we have described. 



Diagnosis. 



In such cases the obstetrist has to ascertain, as Saint-Cyr points out : 

 I. Whether individual twins are present; 2. To distinguish, among 

 the parts which present, those which belong to each foetus. This can 

 only be done by a most careful manipulation, and even then at times the 

 obstetrist will find himself embarrassed. For instance, when the fore 

 feet of one foetus presents along with the head of the other, the operator 

 may be led to believe that there is only one animal to extract ; and as 

 the position is seemingly favorable, and the difficulty only due to exces- 

 sive size of the foetus, powerful traction is resorted to for its removal. 

 This, however, fails to effect its object ; and when another exploration is 

 made, it is discovered that the attempt has so fixed the foetal parts in 

 the pelvis, that the most energetic and skilful manipulation will scarcely 

 move them in order to alter their position. 



In other instances, we fine the limbs of the foetuses so interlocked that 

 they are with the greatest difficulty disengaged. 



Extraction. 



It is evident that, if delivery is to be effected, one foetus must be 

 extracted at a time. They must, therefore, be disengaged, and one 

 pushed forward into the uterus, while the other is carried towards the 

 vulva. When the latter has been born, then the second, if in a wrong 

 position, must be adjusted and removed. 



This is easily written ; those who have had to carr}^ it out in practice 

 jare alone competent to say how difficult it is to execute in the majority 

 of cases. It must be remembered that, as in nearly every other case, the 

 veterinary obstetrist is only called in when the foetuses have been for 

 some time wedged in the pelvic enterance by the uterine contractions, 

 and most likely also by the injudicious manipulations of amateurs or 

 empirics. If he had the advantage of attending the animal before mat- 

 ters had proceeded so far, and the foetuses were still in the abdomen, 

 then the difficulties would be greatly diminished. 



Recognizing the presence of twins, he would select that which is in the 

 most favorable position, cord the head and fore limbs, or the hind limbs 

 if they presented, place them in a good direction for extraction, and by 

 the aid of assistants draw it towards the outlet, while the other foetus is 

 pushed deeper into the uterus. When the first foetus is well into the 



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