A text-book of entomology, including the anatomy, physiology, embryology and metamorphoses of insects, for use in agricultural and technical schools and colleges as well as by the working entomologist . FIG. 147. — Left anterior wing- of a larva 3 days before pupation. The posterior part is rolled up :. prothoracic stigma; 1r. i., internal tracheal triink ; tt: «., tr. e., external tracheal trunk ; p, cavity;a thoracic lejr, with the imaginal bud b. — After Gonin. that the pupal period was the time of formation of the veins. It seems to meprobable that they are derived from the sheath of the p
A text-book of entomology, including the anatomy, physiology, embryology and metamorphoses of insects, for use in agricultural and technical schools and colleges as well as by the working entomologist . FIG. 147. — Left anterior wing- of a larva 3 days before pupation. The posterior part is rolled up :. prothoracic stigma; 1r. i., internal tracheal triink ; tt: «., tr. e., external tracheal trunk ; p, cavity;a thoracic lejr, with the imaginal bud b. — After Gonin. that the pupal period was the time of formation of the veins. It seems to meprobable that they are derived from the sheath of the peritracheal spaces.(Gonin, pp. 30-33.) The appearance of the wing-germs in the fully grown caterpillar,as revealed by simple dissection, is shown at Fig. 146; Fig. 147 136 TEXT-BOOK OF ENTOMOLOGY represents a wing of a larva three days before pupation, with, thegerm of a thoracic leg. A. G. Mayer has examined the late development of the wings inPieris rapie. Fig. 149 represents a frontal section through the left. FIG. 148.—Grabers diagrams for explaining the origin and primary in vacillation of the hypo-dermis to form the germs of the leg (/>), and wings (/, A-C), and afterwards their evaginatioh D,so that they lie on the outside of the body. E, stage B, showing the hypodernial cavities (/) andstalks connecting the germs with the hypodermis (s). — After Graber. wing of a mature larva and shows the rudiment of the wing, lyingin its hypodermal pocket or peripodal cavity. How the trachea passes into the rudimen-tary wing, and eventuallybecomes divided into thebranches, around which themain veins afterwards form,is seen in Figs. 144,147, ir>(.).The histological condi-tion of the wing at thistime is represented by Fig. 1-n;. 1 111. >iTtion lengthwise through the left wing L J of mature larva In li,-rix fti/nr: t, trachea; hyp, hypo- 151, the Spindle-like hypo- (Ic-nnis ; c, cutirula.—After Mayer. dermal cells forming thetwo walls being separated by the ground-mem
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishe, booksubjectinsects
