Half hours with insects . ^ seen. In its pupal stage the mosquito is quite a different life is regulated by a new code. It scorns food of allsorts, and like some religious devotee lives ou air alone, andthat in homeopathic doses. The enormous thorax is almosta deformity, and now, instead of breathing through its tail,it bears two club-shaped respiratory tubes on its back (, (I). These are situated on the site of the future tho-racic spiracles of the fly. 10 ^ 17 146 HALF HOUES WITH ENSECTS. [Packard. Of those insects whicb extract air from the water in whichthey live and are n
Half hours with insects . ^ seen. In its pupal stage the mosquito is quite a different life is regulated by a new code. It scorns food of allsorts, and like some religious devotee lives ou air alone, andthat in homeopathic doses. The enormous thorax is almosta deformity, and now, instead of breathing through its tail,it bears two club-shaped respiratory tubes on its back (, (I). These are situated on the site of the future tho-racic spiracles of the fly. 10 ^ 17 146 HALF HOUES WITH ENSECTS. [Packard. Of those insects whicb extract air from the water in whichthey live and are not obliged to ascend to the surface, is theyoung of the plumed gnat (Fig. 110, CJdronomus oceanicus^male, and beneath, head of female ; a, larva and head en-larged). These worms are very abundant in every mudpuddle, but the species here figured lives at all depths in Fig. Ocean Gnat; a, larva, and head enlarged. the sea down to over a hundred feet. Some larvte of an-other species were dredged in Lake Superior by Mr. S. at a depth of one hundred and fifty-five feet. They areusually provided with two pairs of fleshy filaments, perme-ated by one or two slender tracheal twigs, connecting witha slender pair of tracheae running through the body, and 18 Packard.] IXSECTS OF THE POND AND STREAM. 147 enlarging towards the head. So slightly developed, how-ever, is the tracheal system in Chironomns, and so thin arethe walls of the body, that I am inclined to think that thesenearl}-- transparent larvae breathe in part through their skin. Now we have in the singular ghost-like larva of Corethraanother plumed gnat, a being which has no spiracles nor tra-cheae, and which breathes, as NYeissmann sajs, through theskin. The air thus absorbed is contained in four reservoirs,forming swimming bladders, and thus the density of thewater is measured by this living hyd
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectinsects, bookyear1881
