. Lessons in nature study. Nature study. 76 NATURE STUDT Fig. 49. Yoiiiig L>i-a^ou-fl3'; front. view showing face covered by the fold- ed under-lip. Examine, also, the thin flat blade or oar-like processes at the poster- ior extremity of the slender-bodied young dragon-flies. These are tracheal gills for breathing, and with a magnifier the fine dark branching air-tubes (tracheee) can be seen in them. Observe now the young dragon- flies in the aquarium. If there are some soft-bodied insects in the water, you will not have to watch long before you can see the grasp- ing lower-lip at work. As
. Lessons in nature study. Nature study. 76 NATURE STUDT Fig. 49. Yoiiiig L>i-a^ou-fl3'; front. view showing face covered by the fold- ed under-lip. Examine, also, the thin flat blade or oar-like processes at the poster- ior extremity of the slender-bodied young dragon-flies. These are tracheal gills for breathing, and with a magnifier the fine dark branching air-tubes (tracheee) can be seen in them. Observe now the young dragon- flies in the aquarium. If there are some soft-bodied insects in the water, you will not have to watch long before you can see the grasp- ing lower-lip at work. As an un- suspecting insect swims by the masked face of the young dragon-fly, like a flash the lower lip darts forward and those two fine-toothed grasping flaps at the tip seize the insect, and carry it, as the lip folds up again, to the strong jaws of the captor. The young dragon- flies are very voracious, and they will soon capture and eat most of the other soft bodied insects in the aquarium. The eggs of the dragon-flies are either drop- ped into the water by the females which fly about over the pond, or are placed in slits cut into the stems of water plants. The young dragon-flies youn^j*°dragon'?fly: live for from a few months to nearly a year, gradu fip'^gt'etched out"^'' ally growing larger, and the wings slowly develop- ing. When ready to transform, the young dragon-fly crawls up on the stem of some water plant or projecting stick or stone, out of the water; the skin breaks along the back, and slowly the winged dragon-fly issues. This transformation takes place usually in the early morning hours, and this cannot be conven- iently observed by the class. If you bring into the aquarium, however, a number of young dragon-flies at the time of year (the late spring and early summer) when they are transforming, the process may be observed in the Please note that these images are extracted from scanned page images that may have been digitally enhanced for reada
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