ANOMALIES IN GESTA TION i6i 



to disease, functional disorder, or deformity, and also, doubtless, to their 

 function being only that of reproduction. With regard to anatomical 

 arrangement as averting, to some extent at least, this misplaced gestation, 

 we may point out that of the Mare as typical — though the same indica- 

 tion is applicable to the case of the other large animals. In this creature, 

 the escape of the ovum into the abdominal cavity can only occur through 

 some malformation or anomaly in the conformation of the fimbriated 

 extremity of the tube, which, in the normal condition, is applied to the 

 base of the ovary, and envelops it during the genital excitement. Neither 

 is it likely that its course through the cavity of the tube can be checked, 

 as this is short and direct ; and the comparative thinness of the uterine 

 walls almost precludes the probability of the ovum lodging itself in them. 



Ovarian fcetatton has seldom been observed, so far as my researches 

 have led me ; though its occurrence in the domesticated animals is 

 far from being impossible. It has been divided into two kinds ; internal 

 ovarian^ when the embryo is developed in the Graafian vesicle or interior 

 of the ovary ; and external ovarian^ when the ovum has left the vesicle 

 and grows beneath the envelope of the ovary. The only instances on 

 record are given by Rohlwes, Gurlt, and Plot. The first observed this 

 rare form of gestation in a Mare which had been pregnant twenty-one 

 days. The ovary w^as greatly enlarged, and contained a small embryo in 

 a vesicle. Plot observed it in a Cow, and also in three Sows. 



Tubal foetation^ in which the embryo is developed in the Fallopian tube, 

 is also exceedingly rare, if the paucity of cases reported is any criterion. 

 Rohlwes mentions having found the bones of a foetus in the left Fallopian 

 tube ; and Carus says this form has been noted in the Rabbit. Car- 

 sten Harms speaks of it causing fatal internal haemorrhage, by rupture of 

 the tube, through the incapacity of the latter to distend sufficiently for 

 the development of the foetus. 



In interstitial foitation, the embryo is developed between the membranes 

 forming the walls of the uterus ; the muscular fibres, at the point where 

 this occurs, are separated, and the cyst containing the embryo is situated 

 between the serous and mucous membrane. This variety has not been 

 noted in the lower animals, I believe ; neither have the remaining forms, 

 except the abdominal^ some very rare cases of which are on record. 



Abdominal or ventral foetation, may present two varieties ; the ovum 

 may !;"^it itself, after escaping from the ovary, directly in the* cavity of 

 the abdomen, and there be developed ; or it may be developed at some 

 other point — the ovary, Fallopian tube, etc., and fall into the abdomen 

 after rupture of the pouch which contained it. In the first instance it is 

 WdiXSi^A primary, and in the other secondary abdominal foetatio7i. Extremely 

 rare though both varieties are in animals, yet perhaps the first variety is 

 less frequent than the second. 



The following cases of abdominal fcetation are given as examples : — 



M. Mollard, in the Rccueil de Med. Veterinaire for 1838, gives the case of the foetus of 

 a Goat, which was found in the abdomen of its parent by a butcher. The uterus was 

 perfectly intact, and did not exhibit any trace of gestation ; the foetus itself was attached 

 to the umbilical region of the mother by vessels and very short ligaments, and was 

 enclosed and much compressed by an envelope somewhat resembling the omentum ; 

 this membrane was adherent, throughout its extent, to the skin of the young animal. 

 In this instance there is an absence of anatomical details which detracts from the inter- 

 est and certainty of the case. In a more recent, and perhaps the only sufificiently 

 attested instance of primary abdominal fcetation on record, we find these details very 

 satisfactorily furnished by the able director of the Belgian Veterinary School at Brus- 



II 



