32 



HAND-BOOK OF PHYSIOLOGY. 



of the eye, the fibrous sheath of the testicle; in the fasciae and aponeurosis 

 of muscles, and in the sheaths of lymphatic glands. 



Structure. To the naked eye/ tendons and many of the fibrous mem- 

 branes, when in a fresh state, present an appearance as of watered silk. 

 This is due to the arrangement of the fibres in wavy parallel bundles. 

 Under the microscope, the tissue appears to consist of long, often parallel, 

 wavy bundles of fibres of different sizes. Sometimes the fibres intersect 

 each other. The cells in tendons are arranged in long chains in the 

 ground substance separating the bundles of fibres, and are more or less 

 regularly quadrilateral with large round nuclei containing nucleoli, which 

 are generally placed so as to be contiguous in two cells. The cells consist 

 of a body, which is thick, from which processes pass in various directions 

 into, and partially filling up the spaces between the bundles of fibres. 



FIG. 29. 



FIG. 30. 



FIG. 29. Caudal tendon of young rat, showing the arrangement, form, and structure of the ten- 

 don cells, x 300. (Klein.) 



FIG. 30. Transverse section of tendon from a cross-section of the tail of a rabbit, showing sheath, 

 fibrous septa, and branched connective-tissue corpuscles. The spaces left white in the drawing rep- 

 resent the tendinous fibres in transverse section, x 250. (Klein.) 



The rows of cells are separated from one another by lines of cement sub- 

 stance. The cell spaces can be brought into view by silver nitrate. The 

 cells are generally marked by one or more lines or stripes when viewed 

 longitudinally. This appearance is really produced by the laminar ex- 

 tension either projecting upward or downward. 



(c.) Yellow Elastic Tissiie. 



Distribution. In the ligamentum nuchse of the ox, horse, and many 

 other animals; in the ligamenta subflava of man; in the arteries, consti- 

 tuting the fenestrated coat of Henle; in veins; in the lungs and trachea; 

 in the stylo-hyoid, thyro-hyoid, and crico-thyroid ligaments; in the true 

 vocal cords. 



Structure. Elastic tissue occurs in various forms, from a structure- 

 less, elastic membrane to a tissue whose chief constituents are bundles of 



