A system of obstetrics . (From Haddon): Diagrammatic Trans-verse Section through the Blastodermand Yelk of the Oosperm of a Hypo-thetical Primitive Mammal: ep, epiblastof future embryo; ep, non-embryonicepiblast, which is surrounding the yelk;hy, primitive hypoblast; y, food-yelk. 124 DEVELOPMENT OF THE EMBRYO cells; the [food-] yelk is being surrounded \>y the non-embryonic epi-blast. A [segmenting] oosperm in which the [food-] yelk is sup-posed !<» have been lost is shown in Fig. 19, A. Owing to the absenceof food-yelk, the non-embryonic area of the epiblast, having nothing to. Diagram
A system of obstetrics . (From Haddon): Diagrammatic Trans-verse Section through the Blastodermand Yelk of the Oosperm of a Hypo-thetical Primitive Mammal: ep, epiblastof future embryo; ep, non-embryonicepiblast, which is surrounding the yelk;hy, primitive hypoblast; y, food-yelk. 124 DEVELOPMENT OF THE EMBRYO cells; the [food-] yelk is being surrounded \>y the non-embryonic epi-blast. A [segmenting] oosperm in which the [food-] yelk is sup-posed !<» have been lost is shown in Fig. 19, A. Owing to the absenceof food-yelk, the non-embryonic area of the epiblast, having nothing to. Diagrammatic Transverse Section through a Hypothetical Mammalian Oosperm, after theprimary layers of the blastoderm had been formed by segmentation of the fertilized i _•food-yelk of the original mammalian ovum is supposed to have been Lost |: a,earlier, and B,later Btage of development; ep, embryonic epiblast; ep, non-embryonic epiblast; yt, cavityof blastodermic vesicle enclosed by non-embryonic epiblast (after Haddon). grow around, has precociously completed the blastodermic vesicle,and the [embryonic portion of the] blastoderm lias sunk into the cavity <»rthe empty [blastodermic vesicle]. The non-embryonic epiblast then(Fi<r. 49, B) grows over the embryonic area as the cover-cells (p. 104).In this way would arise something very like what we actually find to Fig. 50.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectobstetrics, bookyear1
