Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 272 EMBRYOLOGY OF INSECTS AND MYRIAPODS dorsoventral flattened sack, one wall of which is the embryo, the other the amnion. At first the amnion and the embryo show a similar cell structure except at the posterior end at the point of invagination. There the amniotic cavity runs out into two furrows (Fig. 202), the inner wall of the invagination representing the prolongation of the amnion
Embryology of insects and myriapods; Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching embryologyofinse00joha Year: 1941 272 EMBRYOLOGY OF INSECTS AND MYRIAPODS dorsoventral flattened sack, one wall of which is the embryo, the other the amnion. At first the amnion and the embryo show a similar cell structure except at the posterior end at the point of invagination. There the amniotic cavity runs out into two furrows (Fig. 202), the inner wall of the invagination representing the prolongation of the amnion, the outer wall the anlage of the germ band. The continuation of the germ band anteriorly is represented by the two ends of the lateral plates, or head lobes, which are still distinctly separated (Fig. 204, hi). When the tail of the invaginating embryo reaches the cephalic end of the egg, it bends and grows caudad until head and tail nearly meet (Fig. 203A). At the point of invagination two amniotic folds appear (Fig. 203A,amf) which fuse, with the result that the embryo lies completely separated from the serosa (Fig. 2035). Nearly the same stage in development of Oncopeltus is represented by Fig. 204, a hi Fig. 202.—Pyrrhocoris. Ventral aspect, {hi) Head lobe.
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