324 SPECIAL HISTOLOGY. 



genous cell-formation is met with in an unusual degree of 

 perfection, and more especially in all kinds of articular cartilages; 

 in which the parent cells, frequently of very considerable size, 

 with one or two generations of secondary cells, and also con- 

 taining fat, lie tolerably free in the fibrous matrix, and admit 

 of being readily isolated, {vide also Ecker in Roser and 

 Wunderlich's 'Archiv/ vol, II, 1813, p. 345). In the adult, 

 the articular cartilages are non-vascular, although the vessels 

 of the synovial membrane, at their border, often advance to 

 some distance over them. What Liston (' Med. Chir. Transact./ 

 1840, pp. 93-4) describes as " vessels in the articular cartilage 

 of several diseased joints, and as running straight in parallel 

 lines from the injected membrane of the bone into the cartilage, 

 and as joining at their further extremities in that tissue, thus 

 forming long loops," were certainly nothing more than the 

 normal vessels of cartilage, which (vide infra) may be very 

 beautifully displayed even in individuals 18 years old. There 

 cannot, therefore, be any question of inflammation of the 

 cartilages in the adult, though they doubtless suffer in morbid 

 conditions of the bones upon which they rest, or in inflam- 

 mation of the synovial membrane. They frequently assume 

 a fibrous structure, a change which is often attended with 

 a simultaneous increase in thickness, Cruveilhier, (' Diet, 

 de Med. et Chir. prat.' Ill, 514) having noticed fibres of 

 this kind as much as 6"' in length, thus far exceeding the 

 normal thickness of articular cartilage. They sometimes wear 

 away rapidly, or even disappear altogether (in suppuration in 

 the bone or in the articulation), so that the surface of the 

 bone is left exposed; they also undergo partial losses of 

 substance ; when they exhibit ulcerous excavations, which may 

 penetrate to the bone, or commence on the osteal surface of 

 the cartilage.] 



§ 96. 



The articular capsules (capsules s. membrance synoviales) are not 

 closed capsules, but short, wide tubular sacs, which are attached 

 by two open ends to the borders of the articular surfaces of the 

 bones, and thus connect them together. They are essentially 

 more or less delicate, transparent membranes, but are in many 

 situations so closely and completely invested externally by 



