. The microscope and its revelations. ile each darkspace is crossed by a lighter band, known as* Hensens stripe. It has been generallysupposed that these markings indicate dif-ferences in the <v///y<ox///o// of the fibre ; butProfessor J. B. Haycraft has revived anidea, which originated with Mr. Bowman,that they are the optical expressions of itsshape. The borders of the striated fibre(he truly states) present wavy margins, in-dicative of a transverse ridging and furrow-ing, the whole fibre (or a single fibril) thusconsisting of a succession of convex bead-like projections with intermedi
. The microscope and its revelations. ile each darkspace is crossed by a lighter band, known as* Hensens stripe. It has been generallysupposed that these markings indicate dif-ferences in the <v///y<ox///o// of the fibre ; butProfessor J. B. Haycraft has revived anidea, which originated with Mr. Bowman,that they are the optical expressions of itsshape. The borders of the striated fibre(he truly states) present wavy margins, in-dicative of a transverse ridging and furrow-ing, the whole fibre (or a single fibril) thusconsisting of a succession of convex bead-like projections with intermediate concavedepressions. When the axis of the fibre is intrue focus, Dobies line, D (fig. 786), crosses the deepest part of the concavity, while Hensens stripe, H, crossesthe most projecting part of the convexity, and it can be shown, boththeoretically and experimentally, that this alternation of lights andshades will be produced by the passage of light through a similarlyshaped homogeneous rod of any transparent substance. If, on tbe. FIG. 786.—Diagram of striated fibrilla. IO5O VERTEBRATED ANIMALS other hand, the surface of the fibre be brought into focus, the convexribbings appear light and intervening depressions dark, which is theaspect originally represented by Bowman. The appearances are thesame in the extended and contracted states of the fibre; with theexception that the alternation of light and dark strife is closer in thecontracted state, while the breadth (representing the thickness) ofthe fibre is correspondingly It is well none the less inthe present state of our knowledge to refrain from conclusions as tothe absolute structure of the striated fibrilla?. It ranges itself, fromthe modern microscopists point of view, with other striated objects,and will require the possession of lenses of a twice or thrice thatof those which are now within our reach. There is no immediate pro-spect of these, it is true; but they cannot be considered impossibleby th
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
