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pedicle , their surface in convex, and perforated by numerous openings, into which the 

 :t.il t nfts pass. They have always a yellowish colour which, added to their 

 tin m the a|.| ataii'-'- of a lno.il mushroom. 



With regard to the ;</>V/I/,T, they repeat, "ii tin- .-nrface of the chorion, the disposition 



of the cotyledons on the uteru-. They are vascular, concave patches, closely embracing 



the cotyledons, and showing on their surface a multitude of lon^ minifying papillae, 



which oury thein-.K..- m t h, .-. t\ l.-donal cavities. They are attached to the chorion by 



v thick, short, vascular pedicle. 



In the Shrtfi and ti<ml the arrangement is the same, except that the cotyledons an- 

 hollowed out in tlieir centre, like a cup, and into this cavity the placenta is inserted. 



Chiirimi. Thi- membrane corresponds to the inner face of the uterus, in the inti-r- 

 plaei-ntal jHiints; its interir.il surface is united Ky lamellar connective tissue to the 

 amnion mxl allantoi.-. Its general form is a repetition of that of the uterine cavity. 



Allnnti'if. -Very different from that of the Mare, and otherwise much less com- 

 plicated, the allantois of Kmninaiits is a very elongated cavity, whose middle portion 

 -i the insertion of the urachus. and whose extremities are prolonged into the two 

 ournua of the chorion. This sac, which is an expansion of the urachus, is always 

 ed on one of the .-ides of the amuion. At times the hippomanes is found floating 

 in the liquid it contains. 



nii.it. Altogether like that of Solipeds, this membrane is readily resolved into 

 two lamina, and presents on its inner surface a great number of little, yellowish-white, 

 epidermic patches, more especially visible on the amniotic covering of the cord. 



I 'inlili'-nl cord. This comprises two arteries and two veins ; the latter forming one 

 trunk on their entering the abdomen. To reach the chorion, these vessels only traverse 

 the amniotic cavity. They ore accompanied by the urachus, which at their extremity 

 - the dilatation that results in the allantoid sac. 



I 'inliili'-iil vesicle. This pouch disappears at an early period, and not a vestige of it 

 is to be found after the formation of the abdominal parietes. 



J. PIG. The placenta is formed by an expansion of the villous tubercles, as in 

 Solipeds. 



The chorion has not a body and two coruua, but is merely an elongated sac, whose 

 two extremities are in relation with the adjacent fetuses. The inner face corresponds, 

 as in Ruminants, with the amnion and allantois. The latter is the same as in the Cow, 

 though it is very much shorter. 



unl'ilical vesicle, amnion, and cord are also the same as in Ruminants. 

 < 'ARNIVORA. The placenta is a thick cincture, surrounding the middle portion of 

 the chorion. The latter resembles that of the Pig. 



The allantois is disposed, in principle, as in Solipeds. 



The umbilical reside, which remains very developed at all periods of foetal life, 

 resembles in shape the allantoi- of the Pig ; being a transversely elongated sac included 

 between the amuion and the inner allantoid lamina, and provided at its middle portion 

 with a narrow pedicle, which id prolonged into the umbilical cord; its walls are 

 extremely vascular. 



Tin <t, union is lined, internally, by the inner lamina of the allantois. 



The umbilical cord lias, as in Solipeds, an allantoid portion ; but it is extremely 

 abort, and envelop, d in a wid>- fold of the allantois. 



-ULTS. Tho comparative examination of the disposition of the placenta may 

 furnish valuable indications as to the procedure to be adopted in practising artificial 

 deli\. -ur^'ical maiio uvres should necessarily vary with the extent and disposi- 



tion of the point.- of union existing between the uterus and the fn-tal t nvelopes. 



With this practical ol.ject in view, we believe that it is useful to divide the 

 domesticate <1 animals into two groups: those which have a sim/il-, and tin-so which 

 have a multiple placenta. The first group may be subdivided, according as the simple 

 placenta in general or local. 



ThU division is summed up in the following table: 



If An . i / Mare. 



nl t 

 I"* a* {!::;:'' 



I Cow. 

 Multiple Placenta { Sheep. 



