. The comparative anatomy of the domesticated animals. Veterinary anatomy. ^""IkhilMI DIAGRAM OP AN EAELY HUMAN OVUM, SHOWING THE AMNION IN PKOOESS OP POEMATION, AND THE ALLANTOIS BEGIN- NING TO APPEAR. a, Chorion; 6, Vitelline mass, surrounded by the blastodermic vesicle ; c, Embryo ; d, e,f, External and internal folds of the serous layer, forming the amnion; g, Incipient' DIAGRAM OP A HUMAN OVUM IN SECOND MONTH, SHOWING THE COMPLETION OP THE SAC OP THE AMNION, AND A PUR- THER DEVELOPMENT OP THE ALLANTOIS. al, Smooth portion of the chorion; a2, Its villous portion; k, k
. The comparative anatomy of the domesticated animals. Veterinary anatomy. ^""IkhilMI DIAGRAM OP AN EAELY HUMAN OVUM, SHOWING THE AMNION IN PKOOESS OP POEMATION, AND THE ALLANTOIS BEGIN- NING TO APPEAR. a, Chorion; 6, Vitelline mass, surrounded by the blastodermic vesicle ; c, Embryo ; d, e,f, External and internal folds of the serous layer, forming the amnion; g, Incipient' DIAGRAM OP A HUMAN OVUM IN SECOND MONTH, SHOWING THE COMPLETION OP THE SAC OP THE AMNION, AND A PUR- THER DEVELOPMENT OP THE ALLANTOIS. al, Smooth portion of the chorion; a2, Its villous portion; k, k, Elongated villi col- lecting into placenta; 6, Vitelline, or um- bilical vesicle; c. Embryo; /, Amnion, inner layer; h, Its outer layer coalescing with the chorion. The umhilical card offers nothing particular. The placenta is circular; its diameter at the termination of pregnancy being from 6 to 8 inches, and its thickness from 1 to IJ inclies. There is distinguished the foetal placenta, m the midst of which the umbilical coril arrives; and the maternal placenta, whose villosities dovetail witli those of the former. The insertion of the placenta takes place towards the fundus of the uterus, near one Of the Fallopian tubes. When there are more than one fcetus, there are a corresponding number of placentae. Independently of those annexes, which are the same in all, there is described for the human fcetus a special envelope, external to the chorion; this ia the membrana decidua. This is formed by the hypertrophied mucous membrane, which is doubled around the ovum, when the latter is lodged in the uterine cavity. Consequently, there results the division of the decidua into two parts : (he true decidua (decidua vera) which covers the uterus, and tbo reflected decidua (decidua reflexa) which envelops the chorion. These present the characters of the hypertrophied uterine mucous Please note that these images are extracted from scanned page images that may have been digita
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Keywords: ., bookauthorchauveauaauguste18271, bookcentury1800, bookdecade1880
