Half hours with insects . wers of the microscope than the larvalMay fly (Fig. 117). The body is so transparent that themovements of the heart, the play of its valves, the circula-tion of the blood, the distribution of the tracheae, the diges-tive canal and its movements, as well as the action of the 22 Packard.] IXSECTS OF THE POND AND STREAM. 151 muscles controllingthe jaws and otherparts of the mouth,can all be watchedwith ease. The tra-cheal gills, like pad-dles, either round orlong and leaf-like,are arranged in pairsalong the hinder re-gion of the body,and the tracheae inthem can be readil
Half hours with insects . wers of the microscope than the larvalMay fly (Fig. 117). The body is so transparent that themovements of the heart, the play of its valves, the circula-tion of the blood, the distribution of the tracheae, the diges-tive canal and its movements, as well as the action of the 22 Packard.] IXSECTS OF THE POND AND STREAM. 151 muscles controllingthe jaws and otherparts of the mouth,can all be watchedwith ease. The tra-cheal gills, like pad-dles, either round orlong and leaf-like,are arranged in pairsalong the hinder re-gion of the body,and the tracheae inthem can be readilyseen. These beauti-ful respiratory leavesare also paddles, andby their aid as well asby the undulations ofthe body the 3oungMay fly moves rap-idly and gracefullythrough the lives two years,while tbe winged fly(Fig. 118) but a day,rarely over twenty-four hours. Thewinged fly throwsoff the pupa skin inan instant. Whileholding a pupa inmy hands the im-ago slipped out sud-denly with wingsfully formed. This Fig. The Horned Corydulus. 23 152 HALP HOURS WITH E^SECTS. [Packard. was the so-called sub-imago ; after a few hours, if it had notbeen placed in the collecting bottle, it would have thrownoff a thin pellicle, and then been sexuall}^ mature. It then Fig. 116. Fig. 117. Fig. lis.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectinsects, bookyear1881
