. The science and art of midwifery . m is covered with a denseforest of villi, presenting the most delicate and graceful characters. We have just noted thai the um-bilical vesicle was a temporary struct-ure, and only for a brief period ofphysiological importance. Mean-time a new organ is developed, bymeans of which a vascular connec-tion is established between the em-bryo and the villi of the organ is termed the allantois begins as a sac-like pro-jection from the posterior extremityof the intestine at the time when theamniotic folds rise up in the formof an embankmen
. The science and art of midwifery . m is covered with a denseforest of villi, presenting the most delicate and graceful characters. We have just noted thai the um-bilical vesicle was a temporary struct-ure, and only for a brief period ofphysiological importance. Mean-time a new organ is developed, bymeans of which a vascular connec-tion is established between the em-bryo and the villi of the organ is termed the allantois begins as a sac-like pro-jection from the posterior extremityof the intestine at the time when theamniotic folds rise up in the formof an embankment around the em-bryo (vide big. 43). At this timethe umbilii al vesicle is still very Large. The allantois, like the umbilical vesicle and the intestine, iscomposed f two layers derived respectively from the hypoblast andthe inner stratum of tin- mesoblast. It speedily becomes vascular, andincreases rapidly in size. The inner surfaces of the sac soon adheretogether, so as to form a Bingle membrane. In the course of the third. Fig. i.). i. exochorion : 8, endochorion ; r,umbilical vesicle; i. amnion; P, pedi-cle of allantois. Plate III.
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Keywords: ., bookcentury1800, bookdec, booksubjectobstetrics, booksubjectwomen
