. Marvels of insect life [microform] : a popular account of structure and habit. Insects; Insectes. fh,4"sl,y] [/.;. Slffi. Beetle and Ant. A Brazilian brt'tlF is hi't¥coiiipan>(l with onr of the largest ants from tte same ngiaa. The tiiubs, aiiU-imx, and jawit, though agrncing in luimber and in i^'iicral slnicturi', jft pnseiit considrrable modifications of fonii. Thp ant is (wicc the balf the .ictual size. of lifo; ih(^ iMTilt . six or eight. All ihu \vinf,'tK! Insects pass through a series of changes, called metamorphoses, after the\- leave the egg, in the last stage having t
. Marvels of insect life [microform] : a popular account of structure and habit. Insects; Insectes. fh,4"sl,y] [/.;. Slffi. Beetle and Ant. A Brazilian brt'tlF is hi't¥coiiipan>(l with onr of the largest ants from tte same ngiaa. The tiiubs, aiiU-imx, and jawit, though agrncing in luimber and in i^'iicral slnicturi', jft pnseiit considrrable modifications of fonii. Thp ant is (wicc the balf the .ictual size. of lifo; ih(^ iMTilt . six or eight. All ihu \vinf,'tK! Insects pass through a series of changes, called metamorphoses, after the\- leave the egg, in the last stage having their wings fully developed. Spiders pass through their developmental stages before they leave the egg, and after hatching merely increase in size without change of form. Insects have only three pairs of true legs ; spiders have four pairs. Owing to the fact that the segments of which an Insect's body is composed are strengthened by the secretion in the outer skin of a substance called chitin—which gives it firmn-jss and serves for the attachment of the muscles—expansion of these to meet the growth of the internal parts is impossible. Tl-e difficulty is met by the throwing off of the old integument, alter a new one has been formt>d beneath. The new one, before the chitin has hardened, expands sutiiciently to permit of a certain period of new growth, and it may be said tliat when an Insect has thrown off an old skin the new one is much larger than is necessary to accommodate the internal parts. This case of chitin reaches its highest development in the beetles, where it forms a hard, rigid armour ; but it is also present in the soft, pliable skin of the beetle's grub, and in that of all other grubs and caterpillars. Let it be clearly understood that the chitin itself docs not constitute the outer covering. As a matter of fact somewhat less than one-half the weight of the skin consists of chitin. This fact may be ascertained by carefully burning, when the animal
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsects, bookyear1915
