. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 410 EMBRYOLOGY OF INSECTS AND MYRIAPODS the molt at the beginning of the second postembryonic developmental period. Consequently the two pairs of ganglia by the constriction of the necks of the depression lose their connection with the ectoderm of the future body wall. The nerve connection between antennae and deutocerebrum is early established. Pflugfelder (1932) states that he made no observations on the
. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. 410 EMBRYOLOGY OF INSECTS AND MYRIAPODS the molt at the beginning of the second postembryonic developmental period. Consequently the two pairs of ganglia by the constriction of the necks of the depression lose their connection with the ectoderm of the future body wall. The nerve connection between antennae and deutocerebrum is early established. Pflugfelder (1932) states that he made no observations on the origin of the tritocerebrum, a part that is poorly developed in the Myriapoda generally. The ganglia of the ventral nerve cord arise in the same manner as the brain lobes with the formation of cup-like invaginations of the ectoderm which are later cut off from the surface. Of these there is a pair for the antennal, mandib- ular, maxillary, and postmaxillary "â â "â¢â¢â¢â¢â¢.... segments and two pairs for each \ of the following segments. Blastokinesis, or flexure of the embryo during development, oc- curs by the folding in of the embryo into the yolk, the bend occurring at about the second maxillary segment leaving only clypeus and telson exposed at the surface (Fig. 368). * . j~ With blastokinesis modifica- tions in certain structures are me- FiG. 368.â Platurhacus amauros. Germ , . ,, i ux i_ i. rr^i. band in surface view after flexure, {ant) chanically brought abOUt. the Antenna, (cly) Clypeus. (tel) Telson. postmaxiUarV segment (second (From Pflugf elder.) ."^ ,, , maxillary) is relatively small, and earlier writers maintained that the appendages were lacking. Pflugf elder has shown that the appendages, though small, are present. They are closer together than the appendages of the maxillae so that when blasto- kinesis takes place the former are pushed between the latter, where they later fuse into a single structure, the gnathochilarium. The ster
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