. The microscope and its revelations. ale presents itself on the footof the Dytiscus (fig. 746, A). The first joints of the tarsus of thisinsect are widely expanded, so as to form a nearly circular plate,and this is provided with a very remarkable apparatus of suckers,of which one disc (ft) is extremely large, and is furnished with strongradiating fibres; a second (b) is a smaller one formed on the sameplan (a third, of the like kind, being often present); whilst thegreater number are comparatively small tubular club-shaped bodies,each having a very delicate membranous sucker at its extremity,
. The microscope and its revelations. ale presents itself on the footof the Dytiscus (fig. 746, A). The first joints of the tarsus of thisinsect are widely expanded, so as to form a nearly circular plate,and this is provided with a very remarkable apparatus of suckers,of which one disc (ft) is extremely large, and is furnished with strongradiating fibres; a second (b) is a smaller one formed on the sameplan (a third, of the like kind, being often present); whilst thegreater number are comparatively small tubular club-shaped bodies,each having a very delicate membranous sucker at its extremity, asshown on a larger scale at B. These all have essentially the same 1 See Mr. Hepworths communications to the Quart. Joitru. Microsc. Sci. vol. , p. 158, and vol. iii. 1855, p. 312. Sec also Mr. Tuffeu Wests memoir On theFoot of the Fly, in Trims. Linn. Soc. xxii. p. 393; Mr. Lownes Anatomy oftin- Bloir-flir, H. Dewitz in Zodlof/ixrJirr An:;eiye>; vi. p. 273; and G. Simmt-r-maclier in u-iss. Zixil. xl. p. 4* FIG. 745.—Foot of flv. IOO2 INSECTS AND AEACHNIDA structure, the large suckers being furnished, like the hairs of thelly s foot, with secreting sacculi, which pour forth fluid through thetubular footstalks that carry the discs, whose adhesion is thussecured ; whilst the small suckers form the connecting link betweenthe larger suckers and the hairs of many beetles, especially (Jurcv- The leg and foot of the J)yti,scus, if mounted withoutcompression, furnish a peculiarly beautiful object for the binocularmicroscope. The feet of caterpillars differ considerably from thoseof perfect insects. Those of the first three segments, which areafterwards to be replaced by true legs, are furnished with strongImriiy claws; but each of those of the other segments, which aretermed pro-legs, is composed of a. circular series of comparativelyslender curved booklets, by which the caterpillar is enabled to clingt the minute roughness of the surface of the leaves. Ar
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
