A text-book of entomology, including the anatomy, physiology, embryology and metamorphoses of insects, for use in agricultural and technical schools and colleges as well as by the working entomologist . tal fold is drawn forwards, and hence the entire hinder segmentmoves forward and is shoved into the front one, and so on with theothers, as at B. Afterwards, if the strain of the muscle is relieved by the diminishing action ofthe tensely stretched, inter-membrane, itreturns to a state ofrest. (Graber.) While we look upon thedermal tube of worms as asingle but flexible lever, thebody of the arth
A text-book of entomology, including the anatomy, physiology, embryology and metamorphoses of insects, for use in agricultural and technical schools and colleges as well as by the working entomologist . tal fold is drawn forwards, and hence the entire hinder segmentmoves forward and is shoved into the front one, and so on with theothers, as at B. Afterwards, if the strain of the muscle is relieved by the diminishing action ofthe tensely stretched, inter-membrane, itreturns to a state ofrest. (Graber.) While we look upon thedermal tube of worms as asingle but flexible lever, thebody of the arthropods, asGraber states, is a linearsystem of stiff levers. Wehave here a series of stiff,solid rings, or hooks, unitedby the intersegmental mem-brane into a whole. Whenthe muscles, extending fromone ring to the next behindcontract, and so on throughthe entire series, the ringsapproximate each other. The ectoskeletal segmentsbend to one side by the con-traction of the muscles onone side, the point of theouter segmental fold oppo-site the fixed point becomingconverted into the turning-point (C). The usual result of thearrangement of the locomo-tive system is the simplecurving of the body (C), and. Fi. ventral longitudinalmuscles = flexors. In /?, the row of segments isstretched ; in A, by the contraction of the musclcsU/)bent upward ; in (\ downward ; ty, tergal; sy, sternalinterarticnlar membranes. — After Lang. then the alternate bending of the body to right and left, which produces the serpentine movements characteristic of theearthworms, the centipede, and many insect larvae. The most strik-ing example of the wonderful variety of movements which can bemade by an insect are those of the Syrphus larva. When feedingamid a herd of aphides, it is se
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishe, booksubjectinsects
