/•;.Y TKA ■ I ' TKI! I .\ K I 'I! KtlX.iyry, 17 ;-, 



Interstitial fcetation is that form in wliicli the cmhryo is developed 

 between the nieinbranes foriniti}^ the walls of the uterus ; the muscular 

 fibres, at the point where this occurs, are separated, and the cyst con- 

 taining the embryo is situated between the serous and mucous mem- 

 brane. 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 fwlation may present two varieties: the ovum 

 may graft 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 named jirimar;/, and in the other secundar// abdominal f'adation. 

 E.\tremely rare though both varieties are in animals, yet perhaps the 

 tirst variety is less frequent than the second. 



Wojinal fa'tation has been recorded as occurring in animals, and the 

 size and conformation of the vagina lends itself to this kind of abnormal 

 pregnancy, which does not appear to be possible in woman. 



Several instances of these different kinds of fcetation are to be found 

 in veterinary literature. 



The length of time during which these extra-uterine foetuses may be 

 retained, varies according to circumstances. In the human species, a 

 case is recorded in which the fcetus remained in the abdomen for lifty- 

 six years ; and a great many instances are published in which retention 

 has continued from three months up to the last-named period. In 

 animals this retention of the misplaced fd-tus may also continue for a 

 long time ; and though death usually occurs if delivery is delayed much 

 beyond the usual period of pregnancy, yet development appears to pro- 

 gress in the ordinary manner, and subject to the laws of normal gesta- 

 tion. It is indeed astonishing to hnd the ovum fix itself, and become 

 developed into the embryo and f<etus, by drawing nourishment in the 

 strange situation in which it chances to fall — the placenta, cord, and 

 envelopes being present just as if it had found its way into the natural 

 receptacle. It does not appear to be (juite decided whether the ovum, 

 in primary abdominal f<etation, receives an additional covering ana- 

 logous to the decidua ; though it is very probable that it does, and that 

 this membrane may perform a similar otlice in the nutrition of the 

 fa'tus. The part of the abdominal or other surface to which the ovum 

 adheres, receives an increased vascular supply for the occasion, its 

 vicarious function being as actively carried on as if it were the lining 

 membrane of the uterus. 



Not infrequently retention is brought to a termination by the death 

 of the parent, through the disordered state of health induced by the 

 living foetus, or through absorption of the septic matter it engenders, if 

 putrefaction sets in after its decease. On other occasions — and these 

 are comparatively not very unusual in the lower animals— an effort 

 is made by nature to get rid of what really in time becomes a foreign 

 body, by artificial openings. In these cases the fcntus may be passed 

 whole or by fragments through the al)dominal parietes, the intestines, 

 or the vagina — in almost every case the former, owing to tlie quadru- 

 pedal position of the domesticated animals. Several occurrences of this 

 kind are to be found in the literature of Veterinarv Science. 



