172 rATHOLOGY OF PREGNANCY. 



intercourse with two different animals within a very short period. If 

 a longer period — say three or four months — intervened, then super- 

 fcetation would be admissible, and would perhaps be undeniable, pro- 

 vided there was nothing abnormal in the uterus — such as a double 

 organ. 



Rainard remarks that torsion of the neck of the uterus in the Cow, 

 though preventing the birth of the foetus, may nevertheless permit new 

 conceptions. "With inversion of the uterus and torsion of the cervix, 

 parturition is impossible ; so that instead of attempting to deliver by a 

 sanguinary and dangerous operation, the success of which is very 

 doubtful, the animal, if not killed for consumption as food, is generally 

 left to the efforts of nature ; should the season be favourable it is 

 allowed to remain at pasture, and freqiaently after some suffering the 

 creature regains its condition, even becomes fat, and may then be 

 advantageously sold to the butcher. Towards the spring-time, such an 

 animal might conceive again without having been delivered of the first 

 foetus. 



In multijyarons animals there can scarcely be a doubt that superfoeta- 

 tion may take place, and perhaps of all those which have been domesti- 

 cated the Rabbit furnishes the most striking example. With this 

 creature a new fecundation may occur in the middle of pregnancy. This, 

 of course, can be accounted for by the anatomical disposition of the 

 generative organs, the two cornua of the uterus opening into the vagina 

 independently ; so that a primary fecundation may occur only from one 

 ovary in the corresponding horn, the other remaining open and un- 

 occupied. 



In the Sow, many instances are published in favour of superfoetation. 

 One of these is given by Miiller, of Hildesheim, in 1887. Twenty-one 

 days after the birth of a litter of six Piglings, the mother Sow became 

 restless and irritable and refused to suckle them. Two days later, that 

 is twenty-three days after birth, a second litter of eleven, all well-formed 

 and healthy, appeared upon the scene. Five of the first and nine of the 

 second litter are still doing well. It is remarked that the mother had 

 access to the Boar for some weeks after the first impregnation, and the 

 authenticity of the account is stated to be beyond dispute. 



In the Bitch, many observers have assured themselves that super- 

 foetation is by no means unfrequent. Rainard, Blaine, and others 

 speak of it. Blaine says, " I am disposed to think that Bitches are 

 capable of superfoetation ; that is, they conceive more than once. If 

 this is the case, a Bitch may copulate to-day, and become impregnated, 

 and in a day or two she may copulate again, and again become impreg- 

 nated. This is not frequent, I believe ; but it certainly does happen, or 

 we could not account for the different periods at which the progeny 

 sometimes appear. I have known a week, and in one case even ten 

 days, intervene between the puppings ; but one or two days is not at all 

 uncommon. As a still more convincing proof, the whelps often appear 

 of different kinds." 



It must be remembered that the bitch remains in " heat " for three 

 or four days, and will seek for repeated intercourse with the male 

 during that period. It must, therefore, either be concluded that the 

 last intercourse was the successful one, or that one or more ova were 

 impregnated at each copulation. 



So far as our knowledge at present extends, we can neither positively 

 negative nor absolutely admit the possibility of superfoetation in the 



