The physiology of the circulation in plants : in the lower animals, and in man : being a course of lectures delivered at surgeons' hall to the president, fellows, etc of the Royal college of surgeons of Edinburgh, in the summer of 1872 . utes the maternalplacental area. In the ruminants this relation is very wellseen, the villous tufts which represent the foetal portion of thecotyledon being torn out of corresponding tufts in the mucouslining, representing the maternal portion of the cotyledon,without rupturing the vessels, and in such a manner as tooccasion no bleeding whatever. This arises f
The physiology of the circulation in plants : in the lower animals, and in man : being a course of lectures delivered at surgeons' hall to the president, fellows, etc of the Royal college of surgeons of Edinburgh, in the summer of 1872 . utes the maternalplacental area. In the ruminants this relation is very wellseen, the villous tufts which represent the foetal portion of thecotyledon being torn out of corresponding tufts in the mucouslining, representing the maternal portion of the cotyledon,without rupturing the vessels, and in such a manner as tooccasion no bleeding whatever. This arises from the fact thatthe capillary vessels of the foetus and mother are simply laidagainst each other, , placed in juxtaposition; the two setsof vessels and the mucous linings investing them remainingessentially distinct. With a view to a natural and easy separa-tion, the maternal and foetal tufts in ruminants are arranged inwedge-shaped masses, the apices of the wedge-shaped capillarymasses of the foetus dovetailing into the capillary wedge-shapedmasses of the mother, an arrangement which admits of very easyextraction. The extraction is further facilitated by the presenceof cotyledonous milk between the tufts (Fig. 60). Tig. Fig. 60.—Cotyledon of cows uterus, a, a, Surface of fatal chorion. b, b, Bloodvessels offatal chorion, c, c, Surface of uterine mucous membrane, d, d, Bloodvessels of uterinemucous membrane.—After Dalton. f. Secretion from utricular glands (cotyledonous milk) placed between maternal and fatalvessels, and which is necessary to the mutual interchange of gases, nutrient, effete, andother matters, between parent and offspring.—Author. 2 108 DR J. BELL PETTIGREW ON THE In man the relation between the foetal villous tufts and thoseof the mother is more intimate than in any other animal, the tuftsthemselves being slightly club-shaped; but even here I am dis-posed to believe that the foetal and maternal tufts are radicallydistinct, and that each is prov
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