PRESENTATIONS OF THE FOETUS. 



233 



Of the different presentations we have enumerated, the anterior — in 

 which the fore feet, head, and chest present simultaneously — is the only 

 one we may designate as " natural," especially with the larger animals 

 and primiparae. 



Fromage de Feugre was the first to point this out, though Ramard was 

 of opinion that the posterior presentation should also be looked upon as 

 normal ; while Desplas gave three natural positions— head and fore limbs, 

 head onlv, and hind limbs only ; and Delwart gives four normal position-^. 

 But experience abundantly proves that the first we have described is that 

 which alone merits the designation, as it is the one in which birth can 

 take place without artificial aid. It is true that birth is possible when 



Fig. 62. 

 Sterno-abdominal Position of the Fcetus. 



the foal or the calf presents posteriorly at the pelvic inlet ; but this is a 

 rare presentation, and under the most auspicious circumstances it is much 

 less favorable, and more difficult for the mother, while it is very often 

 death to the young animal (especially in the Mare). In the majority of 

 cases, without assistance expulsion proceeds no further than the hocks, 

 and the fcetus dies ; and even sometimes with assistance much force is 

 necessary to deliver. Whereas, in the anterior presentation, the cases 

 are exceptional (and these chiefly in primiparge) in which even slight 

 traction is necessary. 



We will follow Saint-Cyr in first studying the mechanism of parturition 

 in this presentation, in which, of the four positions pertaining to it, the 

 vertebrosacral is by far the most frequent and favorable. This we will now 

 notice. 



I. Mechanism of Parturition in the Anterior Vertebra- sacral Position. — In 

 this position it has been stated that the fcetus presents simultaneously 

 with the head and fore limbs, the back directed to that of the mother and 



