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Thus we have explained the formation of those extra-uterine foetuses, which are occasionally met with both in human and veterinary practice.Without describing the earliest stages of the formation of the foetus from the impregnated ovum, vibram five fingers it will be sufficient to remark that in the descent of the ovum into the uterus it receives a coating of effused fibrin, which forms the membrane termed the corium, by which the foetus is attached to the inner surface of the womb, and obtains from the mother the materials necessary for its vitality and growth. The outer surface of the corium (see Plate) is thickly studded in the cowv vibram fivefingers and ewe with shaggy projections, c, named cotyledons, and these are fitted into corresponding concavities, b, in the membrane lining the womb, the tunica decidua uteri, thus forming the bond of connexion we have spoken of. The tufts of the corium contain the vibram five fingers shoes ramification of the foetal vessels, and the concavities of the tunica decidua uteri the enlarged and elongated branches of the uterine arteries of the mother: thus by the two sets of vessels lying in contact, the blood of the foetus is purified and reinvigorated, as the maternal blood is more highly oxygenated than that of the foetus. The change which is effected is a chemical one, and analogous to that taking place in the lungs of an animal after birth ; the cotyledons, vibram five fingers sale therefore, may so far be regarded as the foetal lungs. Besides this important office performed by them, the vessels of the foetus are here surrounded by a thick layer of cells which absorb nutrient matter from the mother and transmit it to the blood of the foetus. Hence the cotyledons may also be compared to the stomach, or rather to the digestive and assimilative five fingers shoes organs of a perfect animal. Thus it will be seen that although there is no direct communication between the vessels of the mother and those of the foetus, yet every requisite for its life and growth is provided for.the force of a blow. The liquor amnii, with its investing membrane, is also made to serve a no less important office, that of being protruded into the mouth of the womb at the commencement of parturition, thus acting as a hydrostatic dilator.The allantoid membrane is situated between the amnion and corium, where it forms a sac to receive the urinary secretion of the foetus: it is of large size in the lower animals, and its dimensions increase with the growth of the foetus, a phenomenon which is not observed in the human subject. The allantoid sac Mbt shoes clearance sale has a direct communication with the true urinary bladder by means of the urachus (see Plate, f). The umbilical cord, h, is composed of this tube, the urachus, and the arteries, i, which convey the impure blood out of the body of the foetus to the cotyledons, and the veins,_/, which return it after having been re-oxygenated in the manner previously alluded to. It will be evident from the foregoing remarks, that a due provision is made for an equal distribution of this pure blood through the body of the foetus, so that every part of the frame may be built up at the same time;