WHITE FIBROUS TISSUE. Ill 



texture closely resembling certain forms of white 

 fibrous tissue, tliere are some fibres exhibiting the re- 

 actions of yellow elastic tissue. These fibres differ in 

 character and number in different cases. Some of 

 them consist of elastic tissue developed from nuclei 

 or masses of bioplasm, as will presently be described. 

 But in many cases these fibres are probably the re- 

 mains of nerve fibres or capillary vessels which had 

 been active at an earlier period of life, while, in some 

 instances, they result from the prolongations of the 

 bioplasm being converted into imperfectly developed 

 fibrous tissue, which, like bioplasm itself, is not ren- 

 dered transparent and caused to swell up by the 

 action of acetic acid. 



162. Wliite flbrous tissue consists of a firm, hard, 

 whitish material which becomes converted into gela- 

 tine by boiling. The toughness and resisting pro- 

 perty of skin depend upon this tissue. The bioplasm 

 of all kinds of white fibrous tissue niay be shown to 

 be continuous with the fibrous tissue or formed ma- 

 terial. If a small portion of white fibrous tissue, as 

 tendon, be examined at a very eai-ly period of deve- 

 lopment Tinder a power of 200 diameters, it will be 

 found that it is composed of oval masses of bioplasm, 

 with a very little intervening fibrous structure. At a 

 still earlier period of its existence, it contained a still 

 larger proportion of bioplasm. As growth proceeds, 

 the fibrous material increases, and the bioplasm, rela- 

 tively decreases, so that when it reaches its adult 

 form the principal portion of the structm-e consists of 

 fibrous material, and there is comparatively only a 

 very small amount of bioplasm. To state this more 

 clearly — In equal portions of young and adult tendon 

 the proportion of bioplasm is very different. There 

 may be five or six times as much in the former as in 

 the latter. This important fact will be demonstrated 

 quite easily if a piece of young tendon be contrasted 

 with a portion from an old subject. The contrast be- 



