26 NORMAL HISTOLOGY. 



The elastic fibres usually occur as networks of highly refracting homo- 

 geneous fibrils which lie among the bundles of white fibres. The individual 

 fibres are much thicker than the white ones and, although differing in width, 

 maintain a constant diameter until augmented by fusion with other elastic 





Connective tissue cell 



Connective tissue cells C 



K 



Migratory colorless 

 blood -cells 



Bundles of white fibres 



Elastic fibres 



FIG. 34. Section of subcutaneous tissue, showing constituents of areolar tissue. X 300. 



fibres. So long as the tissue in which they lie maintains its normal tension, 

 the elastic fibres remain taut and approximately straight, but when disso- 

 ciated, as in teased preparations, they assume a characteristic form and 

 become wavy, bowed or coiled. The proportion of elastic fibres in fibrous 

 connective tissue is, ordinarily, 

 small, conferring only a moderate 

 degree of elasticity. In certain 

 localities, however, as in the liga- 

 menta flava of man and the nuchal 



FIG. 35. Portions of isolated elastic fibres from 

 ligamentum nuchae of ox. X 375- 



Interfibril- 

 lar connec- 

 tive tissue 

 Nucleus of 

 connective 

 tissue cell 



FIG. 36. Transverse section of ligamentum nuchae 

 of ox. X 45- 



ligament of the lower mammals, almost the entire structure is made up of 

 robust elastic fibres, held together by a small amount of intervening white 

 fibres. In transverse sections of such ligaments (Fig. 36), the individual 



