WHITE FIBROUS TISSUE. 277 



10 per cent, be used, and the transparent mass may be torn with 

 equal ease in any direction. If, however, the potash be now re- 

 moved by acetic acid, the original texture returns. (Paulsen.) 

 While acetic acid obscures the parallel lines, and renders the mass 

 transparent, it usually brings into view broken, elongated cor- 

 puscles, the remains of the developmental cells. (Kolliker.) The 

 addition of a mineral acid brings the lines into view again. 



It is the white fibrous tissue which some histologists have termed 

 the collagenous element of the areolar tissue, and the fibrillated col- 

 lagenous 1 substance. It will be frequently termed the " collagenous 

 tissue" and the "collagenous element," in the subsequent portions of 

 this work. 



Properties and Uses of White Fibrous Tissue. 



White fibrous tissue, like the yellow fibrous, manifests no vital 

 properties (save the power of securing and maintaining its develop- 

 ment), but physical properties merely, viz: great strength, great 

 flexibility, and almost total inextensibility. It may, however, be 

 somewhat extended by a slowly-acting and long- continued force. 



The strongest cords used -in the arts are made of this tissue as 

 musical strings, &c. Mascagni calculated that the human tendo- 

 Achillis will sustain a weight of 1,000 pounds. 



Its flexibility is owing to the water it contains. When dried, it 

 becomes quite rigid. In this state, also, it completely resists the 

 putrefactive process. 



Uses. In all cases, where a tissue, strong, flexible, and totally 

 inextensible, is needed, this is the one found. Ligaments and ten- 

 dons are composed almost exclusively of it. Its uses in particular 

 parts and organs vary, as seen in the following paragraphs. Some- 

 times it is merely protective of the softer parts it incloses ; as in 

 case of the sclerotica, the tunica albuginea testis, &c. 



Distribution of the White Fibrous Tissue. 



1. White fibrous tissue constitutes the greater portion of tendons, 

 aponeuroses, and articular ligaments. It also constitutes a large 

 portion of the fibrous membranes, so called viz., the periosteum, 

 perichondrium, and dura mater and enters with the yellow fibrous 

 into the formation of the areolar tissue. Hence it forms the greater 



1 From KoXXa, glue, gelatine, and y^o? ; gelatine-producing ; synonymous with 

 gelatigenous. 



