. British insects : a familiar description of the form, structure, habits, and transformations of insects. of jaws, those of each upon each other, from side to idea of the arrangement of the mouthmay be formed from the accompanyingdiagram, in which a represents the upperlip, or labium ; B, the lower, or labrum; c c,the upper pair of jaws, or mandibles; d d,the lower pair, or maxillse. (See also fig. 6, p. 32.) Insects are divided primarily into biting and suck-ing insects, and while the parts just named are easilyrecognised in the first division, they are in the secondso di
. British insects : a familiar description of the form, structure, habits, and transformations of insects. of jaws, those of each upon each other, from side to idea of the arrangement of the mouthmay be formed from the accompanyingdiagram, in which a represents the upperlip, or labium ; B, the lower, or labrum; c c,the upper pair of jaws, or mandibles; d d,the lower pair, or maxillse. (See also fig. 6, p. 32.) Insects are divided primarily into biting and suck-ing insects, and while the parts just named are easilyrecognised in the first division, they are in the secondso diflTerently developed and modified as to be hardlytraceable, except by such a process as that describedin chap, i., for tracing the relationship between thehorses foreleg, the birds wing, and the arm of a man. The mouth of a beetle affords an excellent exampleof all these parts, as they are found in biting insectsFig. 3 represents the top of the head of a Tiger-beetle (PI. L, fig. 1), and shows the situation of the A c C d B d 30 INSECTS. mandibles, which are very large in this insect—a for- Pig. a Head of Tiger-beetle, (magnified) with jaws Ditto, with jaws open. midable pair of pincerswhen extended as in thefigure (6), and lying quiteacross each other whenclosed (a). These organsare even larger and moreconspicuous in the male ofthe Stag-beetle, whilst inmost other beetles theyare much smaller and lesspowerful. The second pair of jaws,or the maxillee (fig. 4), aremore complicated anddelicate. The principalparts of the maxilla are a kind of blade {a), fringed with hairs, and an antenna-likeFig. 4. Fig. 5. feeler or palpus (6), called the maxil-lary palpiis. Inthe Tiger-beetle andsome other preda-ceous beetles thereis a second appen-dage (c) resemblinga less developed pal-pus. The upper lip is ahorny plate, withoutappendages. The lower lip, or la- 4. Maxilla of Tiger-beetle (highly magnified), i^ • „ ^ /ft o- ^-s ,• „ „p„^ 5. Labium of Tiger-beetle. ^°
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Keywords: ., bookauthorme, bookcentury1800, bookdecade1870, booksubjectinsects
