ClipArt ETC
"Origin of amnion and allantois. 1. Rise of amniotic folds (a.f.) around embryo (e); p.p., pleuro-peritoneal cavity; y., yolk. 2. Further growth of amniotic folds (a.f.) over embryo and around yolk. 3. Fusion of amniotic folds above embryo; a.p., amnion proper; s.z.m., subzonal membrane; y.s., yolk-sac. 4. Outgrowth of allantois (al.); amniotic cavity (a.c.); h., head end; t. tail end. 5. Complete enclosure and reduction of yolk-sac (y.s.); s.z.m, subzonal membrane; a.p., amnion proper; al., allantois; g., gut of embryo." -Thomson, 1916

Reptile Development

"Origin of amnion and allantois. 1. Rise of amniotic folds (a.f.) around embryo (e); p.p., pleuro-peritoneal…