WHITE AND YELLOW FIBROUS TISSUES. 



715 



Fig. 375. 



effect of Acetic acid, which swells it up and renders it transparent, 

 at the same time bringing into view certain oval nuclear particles 

 of 'germinal matter,' which 

 are known as ' Connective- 

 Tissue - corpuscles.' (§ 540). 

 These are relatively much 

 larger, and their connections 

 more distinct, in the earlier 

 stages of the formation of this 

 Tissue (Fig. 376). It is per- 

 fectly inelastic ; and we find it 

 in such parts as Tendons, or- 

 dinary Ligaments, Fibrous 

 Capsules, &c, whose function 

 it is to resist tension without 

 yielding to it. It constitutes, 

 also, the organic basis or 

 matrix of Bone ; for although 

 the substance which is left 

 when a Bone has been 

 macerated sufficiently long in 

 dilute Acid for all its Mineral 



White Fibrous Tissue from Ligament. 



Fig. 376. 



components to be removed, is commonly designated as Cartilage, 

 this is shown by careful Microscopic analysis 

 not to be a correct description of it ; since 

 it does not show any of the characteristic 

 structure of Cartilage, but is capable of 

 being torn into lamellae, in which, if suffi- 

 ciently thin, the ordinary structure of a 

 Fibrous Membrane can be distinguished. — 

 The Yellow fibrous tissue exists in the form 

 of long, single, elastic, branching filaments, 

 with a dark decided border ; which are dis- 

 posed to curl when not put on the stretch 

 (Fig. 377), and frequently anastomose, so as 

 to form a network. They are for the most 

 part between 1 -5000th and 1-1 0,000th of an 

 inch in diameter ; but they are often met 

 with both larger and smaller. This tissue 

 does not undergo any change, when treated 

 with Acetic acid. It exists alone (that is, 

 without any mixture of the White) in parts 

 which require a peculiar elasticity, such as 

 the middle coat of the Arteries, the Vocal 

 Cords, the Ligamentum Nucha? of Quadru- 

 peds, the elastic ligament which holds toge- 

 ther the valves of a Bivalve shell, and 

 that by which the claws of the Feline 

 tribe are retracted when not in use : and 



Portion of young 

 Tendon, showing the 

 corpuscles of Ger- 

 minal Matter, with 

 their stellate prolon- 

 gations, interposed 

 among its fibres. 



