156 PA THOLOG Y OF GESTA TION. 



BOOK III. 



PATHOLOGY OF GESTATION. 



Tu'E. pathology of gestation may be said to include those diseases and ac- 

 cidents which constitute deviations from the regular or normal series of 

 physiological phenomena characteristic of this condition. These devia- 

 tions are somewhat numerous and various, and we will follow Saint-Cyr 

 in classing them under three distinct heads : anomalies, diseases, and acci- 

 dents. We will study these in this order. 



CHAPTER I. 

 Anomalies in Gestation. 



^The anomalies occurring in gestation are superfcetation, extra-uterine 

 pregnancy, and spurious pregnancy. 



SECTION I. — SUPERFCETATION. 



The term superfoetation {fo'Jus super fcetutn — one foetus on another) has 

 been employed to designate those cases of conception in which an ani- 

 mal, already pregnant, has been supposed to conceive a second time be- 

 fore the termination of the primary gestation. In ordinary double or 

 triple gestation, the same copulation has produced the young at once ; 

 but in superfoetation they are supposed to be formed at a more or less 

 wide interval of time, and of course by different copulations. 



The belief in the possibility of such an occurrence in woman was com- 

 mon among the old writers, and cases are adduced in support of this 

 view ; but its correctness has been much disputed by some recent au- 

 thorities. 



Aristotle admitted the likelihood of superfoetation taking place in 

 woman, because during pregnancy she was always with her husband ; 

 but he denied its possibility in the Mare, although he was aware that it 

 might receive the male several times. In all probability, he imagined 

 that the instinct of the Mare would repel the stallion after impregnation. 

 The naturalists and hippiatrists who succeeded him, have also denied 

 that such an abnormal occurrence could take place in the Mare ; be- 

 cause, they declared, after conception the orifice of the uterus is closed, 

 so that the semen of the male cannot be introduced ; every double birth, 

 they also maintained, was due to two ova being impregnated at the one 

 copulation. 



But numerous facts recorded by competent authorities, would go to 

 prove that superfoetation is not only probable, but possible ; and that if, 

 generally, there is only one successful copulation possible, on the other 

 hand there are instances well vouched for, in which two successive copu- 

 lations have been followed by two independent impregnations. In unip- 

 arous animals such cases have been frequently observed, the most con- 

 vincing of which is the production of a mule-foal and a horse-foal by the 

 same Mare at one birth. 



An occurrence of this kind is mentioned in the Memoires de VAcademie Royale des 

 Sciences for 1753 ; a Mare at Chatillon-sur-Sevre brought forth a horse and a mule foal. 



