. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. OLIGONEPHRIDIA 257 of the species have a glabrous surface. The anterior end, as with the egg of the sucking lice, is provided with an operculum that bears the micropylar openings, and at the posterior end there is a stigma with a fine canal which nearly or actually penetrates the chorion. The Pigeon Louse (Lipeurus haculus L.) As with the sucking hce the infec- tion of the eggs of the pigeon louse with symb
. Embryology of insects and myriapods; the developmental history of insects, centipedes, and millepedes from egg desposition [!] to hatching. Embryology -- Insects; Embryology -- Myriapoda. OLIGONEPHRIDIA 257 of the species have a glabrous surface. The anterior end, as with the egg of the sucking lice, is provided with an operculum that bears the micropylar openings, and at the posterior end there is a stigma with a fine canal which nearly or actually penetrates the chorion. The Pigeon Louse (Lipeurus haculus L.) As with the sucking hce the infec- tion of the eggs of the pigeon louse with symbionts takes place during a late period of oogenesis. The symbionts wander singly from the mycetocytes up the egg tube (ovariole) and thence into a depression at the posterior pole of the egg. With the invagination of the germ band the symbionts are carried more deeply into the yolk (Fig. 181) but without the close association with the germ band characteristic of Pediculus. The germ band and its envelopes are formed as in Pediculus. Yolk cells penetrate the mass of symbionts, the yolk meanwhile having become divided into spherules. At the time the anlage of the mid-gut epithelium makes its appearance, forming in the same way as in Pediculus, the symbiont masses, each with a yolk cell as nucleus, become surrounded by a membrane, thus form- ing mycetocytes. In the male embiyos the mycetocytes migrate through the mid-gut epithelium and into the fat bodies. Ries (1931) failed to find mycetocytes in the fat of female embiyos and therefore assumed that they all pass into the ampullae of the reproductive organs, where they may readily be demonstrated in the young female. Here they are binucleate in contrast to those found in the embryo and the larva. Fusion of serosa and amnion before rupture of the membranes, revolution of the embryo, formation of the dorsal organ, and final absorption of this in the yolk take place as with Pediculus. The Guinea-pig Louse (Gyropus ovalis N.) The devel
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Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
