. A manual for the study of insects. Insects. Fig. ioo.â Tracheal gill of Agrion, their rapidly moving wings throwing out gleams of metaUic color as they go. Still more beautiful are they when at rest, their wings wide-spread or folded together above the ab- domen, and as rigid and motionless as if made of iridescent glass; and their great compound eyes shining like gold or precious stones. But for all their terrible names Dragon- flies are entirely innocent of any harm to mankind. They neither sew up people's ears, as northern chil- dren think ; nor bring dead snakes to life, as colored peopl
. A manual for the study of insects. Insects. Fig. ioo.â Tracheal gill of Agrion, their rapidly moving wings throwing out gleams of metaUic color as they go. Still more beautiful are they when at rest, their wings wide-spread or folded together above the ab- domen, and as rigid and motionless as if made of iridescent glass; and their great compound eyes shining like gold or precious stones. But for all their terrible names Dragon- flies are entirely innocent of any harm to mankind. They neither sew up people's ears, as northern chil- dren think ; nor bring dead snakes to life, as colored people in the South believe; but they are very fierce enemies to their insect kindred. Their long, narrow, closely netted wings are strong, carrying them swiftly; and their jaws are powerful, and their appetites good; so it is an unfortunate insect that falls in their way. The mother Dragon-fly lays her eggs in water or fastens them to aquatic plants. The young as soon as hatched swim off and hunt for some smaller creatures to eat. They have strong legs and big jaws, and are real in- sect ogres. The lower lip when extended reaches far out, and is armed with powerful hooks with which to grab their prey; but when fold- ed up it is so large that it is called a mask and gives the insect's face a comical re- semblance to that of a bull-dog. These nymphs have a peculiar method of breath- ing. The caudal end of the alimentary canal is lined with tracheae. The insect alternately draws water into this cavity and expels it; and thus the air in these trachese is purified, this part of the alimen- tary canal acting as a tracheal gill. This process also helps the insect in swimming, . , for the water may be expelled with such Fig. ioi.âExuviae of ^ *â nymph of Dragon-fly. force that the wholc body is sent forward. In some species the nymphs have also two or three large. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability -
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectinsects, bookyear1895
