Chap.v.] FIBROUS CONNECTIVE TISSUES. 



43 



The same modes of formation of connective tissue 

 may be also observed in the adult under normal and 

 pathological conditions. 



50. Fibrous connective tissue is in most places 

 associated with elastic fibres or yellow elastic tissue. 

 These are of bright aspect, of variable thickness and 

 length, branching 



and anastomos- 

 ing so as to form 

 networks (Fig. 

 29). They are 

 straight or more 

 or less twisted 

 and coiled. The 

 latter condition 

 may be observed 

 when the tissue 

 is shrunk, the 

 former when it 

 is stretched. 

 They do not 

 swell up in acids 

 or alkalies, nor 

 yield glutin or 

 gelatin on boil- 

 ing, but contain 



a chemically different substance, viz., elastin. 

 broken their ends generally curl up. 



51. Elastic fibres occur in great numbers as net- 

 works extending between the bundles of fibrous tissue, 

 in the skin and mucous membranes, in the serous and 

 synovial membranes, and in the loose interstitial con- 

 nective tissues. They are not very commonly met 

 with in tendons and fascia? ; in the former they are 

 seen as single fibres often twisting round the tendon 

 bundles. 



Elastic fibres forming bundles, but branched and 



Fig. 29. From a Preparation of the Mesentery. 



a, Bundles of fibrous tissue; 6, networks of elastic 

 fibres. (.Atlas.) 



When 



