OTHER CAUSES OF MATERXAL I'YsToKIA. 3r>7 



to ^Yithill a few lines of its point. The instrument is to be directed to 

 the part where the os is supposed to be ; then the coats of the uterus 

 are to be carefully incised to a small extent — layer after layer, until 

 the escape of the liquor amnii announces that the fd'tal membranes are 

 opened. The small slit thus made is to be enlarged by a probe-pointed 

 bistoury — the enlargement being either crucial or T-shaped. Then the 

 foetus is to be extracted. 



Hubert has performed this opei-ation once on a Sheep, and a shepherd 

 by his direction also performed it on another Sheep, and in both cases 

 the result was favourable for mother and offspring. 



CHAPTER lY. 

 Other Causes of Maternal Dystokia. 



There are some other causes of Dystokia which, though comparatively 

 rare, yet deserve the attention of the veterinary obstetrist, and will 

 complete our notice of the maternal obstacles to parturition. These 

 are: (1) Anomalies of the placenta; (2) Morbid adhesion heticecn the 

 fa:tus and uterus; (3) Stricture of the uterus by external bands; 

 (4) Persistent hymen ; (5) Vatjinal and vulvar atresia. 



1. Anomalies in the Placenta, 



We are but little acquainted with the morbid alterations of the 

 fcetal membranes of animals, and of those changes which lead to their 

 more or less permanent adhesion to the foetus and the uterus. The 

 subject appears to have received very little attention, and the observa- 

 tions are so few that Saint-Cyr makes no mention of these adhesions 

 as a cause of difHicult or impossible birth. 



It is very probable that animals are less subject to disease of the 

 uterus and the placental membranes than the human species, and tliis 

 would account to a certain extent for the absence of notice of such 

 occurrences. Nevertheless, that animals are disposed to metritis, endo- 

 metritis, and perimetritis, no one can deny ; and that we may also 

 have such anomalies as hyperplasia of the chorion, as well as myxomata 

 of that membrane, in addition to new formations of the placenta, as 

 well as placentitis, might be expected. But, as we have observed, 

 there is indeed but little direct evidence to prove that any of these 

 morbid conditions ever exist, thougli some of them at least may lead 

 to abortion, while others might give rise to obstacles which would 

 retard or altogether prevent birth. 



Scirrhous Chorion. 



According to Cox,^ scirrhous chorion is occasionally met with in 

 animals, and proves an obstacle to parturition. 



The membrane is found to be separated from the uterus, and envelops 

 the fcetus, as it were, in a leather bag, no part of the creature being 

 distinguishable. This is probably the condition known in woman as 

 7nyxo)na fibrosum placcntiv. 



The labour pains are seldom violent, though the foetal membranes 



' Veterinary Journal, 1877, p. 105. 



