en. iv.] 



FIBROUS TISSUE 



41 



The fibres are subsequently deposited in this matrix. At one time 

 it was believed that the cells themselves became elongated and 

 converted into fibres. No 

 doubt the cells do exercise 

 a controlling influence on 

 fibre - formation in their 

 neighbourhood, but it is 

 certain that they never 

 become fibres. The forma- 

 tion of fibres is intercel- 

 lular. Some of the fibres 

 formed are of the white, 

 others of the yellow variety. 

 In the case of the elastic 

 fibres, rows of granules of 

 elastin are first deposited ; 

 these joining together in 

 single or multiple rows form 

 the long fibres : traces of this are seen in transverse markings occa- 

 sionally noticeable in the larger elastic fibres. 



FIG. 59. Development of elastic tissue by deposition of 

 fine granules, g, Fibres being formed by rows of 

 elastic granules ; P, platelike expansion of elastic 

 substance formed by the fusion of elastic granules. 

 (Eanvier.) 



Fibrous Tissue. 



This is a kind of connective tissue in which the white fibres pre- 

 dominate ; it is found in tendons and ligaments, in the periosteum, 



dura mater, true skin, the sclerotic 

 coat of the eye, and in the thicker 

 fasciae and aponeuroses of muscle. 



The tissue is one of great 

 strength; this is conferred upon 

 it by the arrangement of the fibres, 

 the bundles of which run parallel, 

 union here, as elsewhere, giving 

 strength. The fibres of the same 

 bundle now and then intersect each 

 other. The cells in tendons (fig. 

 61) are forced to take up a similar 

 orderly arrangement, and are ar- 

 ranged in long chains in the ground - 

 substance separating the bundles of 

 fibres, and are more or less regu- 

 larly quadrilateral with large round 

 nuclei containing nucleoli, which are generally placed so as to be nearly 

 contiguous in two cells. Each of these cells consists of a thick body, 

 from which processes pass in various directions into, and partially fill 



FIG. 60. Fibrous tissue of tendon, consisting 

 mainly of white fibres. (Strieker.) 



