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 NEUROPTERA AND COLEOPTERA 295 brown. The yolk consists of globules of varying size which are sur- rounded by cytoplasm which, however, is not arranged as a reticulum at this time. The periplasm (Figs. 234, 235) surrounding the yolk in some cases seems to consist of two layers: an outer one which stains more lightly than the inner layer. At the posterior pole of the egg an irregular -M
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 NEUROPTERA AND COLEOPTERA 295 brown. The yolk consists of globules of varying size which are sur- rounded by cytoplasm which, however, is not arranged as a reticulum at this time. The periplasm (Figs. 234, 235) surrounding the yolk in some cases seems to consist of two layers: an outer one which stains more lightly than the inner layer. At the posterior pole of the egg an irregular -M Fig. 234.—Brachyrhinus. Section through oosome. (pr) Periplasm. mass, sometimes saucer shaped, can be seen lying partly in the periplasm and partly in the yolk. This is the oosome, or germinal cytoplasm. The vitelline membrane is difficult to make out, and the chorion is so thin and elastic that it can easily be removed after being pricked with a needle. The location of the pronucleus at the time of oviposition has not been determined with any degree of certainty. In several eggs prior to the 'X A-'V -rS:^;4^t>-
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