Handbook of physiology / by W. D. Halliburton.

  • Kirkes, William Senhouse, 1823-1864.
Date:
1909
Catalogue details

Licence: Public Domain Mark

Credit: Handbook of physiology / by W. D. Halliburton. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    this dark field; if it remains dark it is singly refracting. The sarco- plasm is singly refracting or isotropous; it remains dark in the dark field of the polarising microscope. The muscle columns or sarcostyles are in great measure doubly re- fracting or anisotropous, and ap- pear bright in the dark field of the polarising microscope. The sarco- style, however, is not wholly doubly refracting; the sarcous elements lt;,;lj£1J.t»;St*»*»»M«»»M»»»M»»»«*»»»IMSJ-6#.J9^ tfi S i*' * ^'••••••••••••••••••••♦•••tttjtSiVaiJ -'.. - -ztut»iMMumiimMMinanic::: ■; ; t'-'^iC IIMIf M •■MMMMMMHIIWIMIWeesi ;' Fie;. 84.—Wave of contraction passing over a mus- cular fibre of water-beetle, r, r, Portions of the fibre at rest; c, contracted part; i, i, inter- mediate condition. (Schafer.) Fig. 85.—This figure (after Engelmann) illus- trates the appearance of a muscular fibre as examined in ordinary light (left-hand side) and in polarised light (right-hand side). In the upper part of the diagram the fibre is not contracted, in the lower part it is contracted. The dark bands are seen to be bright by polarised light, owing to their being doubly refracting or anisotropous; during contraction, fluid passes from the singly refracting or isotropous light band into the doubly refracting dark band, which, in conse- quence, becomes widened out. are doubly refracting, and the clear intervals are singly refracting. On contraction there is no reversal of these appearances, though of course the relative thickness of the singly refracting intervals varies inversely with that of the doubly refracting sarcous elements (see