HANDBOOK OF PHYSIOLOGY. 



their fi-ee ends usually curl up. (5.) They are of a yellowish tint, and 

 very elastic. 



FIG. 31. Fibrous tissue of cornea, showing 

 bundles of fibres with a few scattered fusi- 

 form cells lying in the inter-fasicular spaces. 

 X 400. (Klein and Noble Smith.) 



FIG. 32. Elastic fibres from the ligamenta 

 subflava. x 200. (Sharpey.) 



These fibres yield a gelatinous substance called elastin. 



Varieties of Connective Tissue. 

 I. FIBROUS CONNECTIVE TISSUES. 



A. Chief Forms. (a.) White Fibrous Tissue. 



Distribution. Typically in tendon; in ligaments, in the periosteum, 

 and perichondrium, the dura mater, the pericardium, the sclerotic coat 

 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 

 membranes, 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, bundles of fibres of different sizes. The fibres of the 

 same bundle now and then intersect each other. The cells in tendons 

 (Fig. 34) 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. The rows of cells 

 are separated from one another by lines of cement substance. The cell 

 spaces can be brought into view by silver nitrate. The cells are gene- 



