260 



FIBRO-CARTILAGE. 



haling the odour of roasted meat, and partly 

 sublimes : it is difficultly soluble in alcohol. 

 It dissolves in nitric acid, and yields on eva- 

 poration a white crystalline compound, the 

 nitro-leucic acid. The portion of the original 

 residue which is insoluble in alcohol (3) is 

 yellow, and its aqueous solution is precipi- 

 tated by infusion of galls, subacetate of lead, 

 nitrate of mercury, and persulphate of iron. 

 It appears therefore that the products of the 

 action of sulphuric acid upon the fibrine of 

 muscle, are, 1, an extractive matter soluble in 

 alcohol; 2. leucine; and 3. extractive, inso- 

 luble in alcohol but soluble in water. 



(W. T. Erande.) 



FIBRO-CARTILAGE, (Cartilago liga- 

 mentosa \.fibrosa ; Fr. Tissu fibrocartilagineux ; 

 Germ. Faser-Knorpel oder Band-Knorpel). 

 As early as the time of Galen we find certain 

 organs distinguished by the appellation vtvgo- 

 Xovfyu&s o-fv^o-jLtot, and Fallopius uses a 

 similar term, namely, chondrosyndesmos, as 

 denoting a substance distinct from true carti- 

 lage. Haase* also, who wrote in 1747, speaks 

 of two structures different from true cartilage, 

 under the names of cartilagines ligamentosee 

 and cartilagines mixt<c. Bichat likewise recog- 

 nised a class of tissues distinct from pure 

 cartilage, and by him it would appear that the 

 namejibro-cartilage was first employed. 



It is evident that no organ should be classed 

 under the head of fibro-cartiluge unless it con- 

 sist distinctly of fibrous tissue and cartilage 

 intermixed, and thus combine not only the 

 structure but the properties of both, the strength 

 and power of resistance of the one, and the elas- 

 ticity of the other ; nevertheless, we shall find, 

 in examining the various structures which are 

 admitted by anatomists to be fibro-cartilaginous, 

 that the fibrous tissue predominates in such a 

 manner as to justify Beclard in regarding fibro- 

 cartilage as a portion of the ligamentous struc- 

 ture, which might be designated cartilaginiform 

 ligamentous organs. The distinction was fully 

 admitted too by Mr. Hunter in reference to 

 the texture of the so-called inter-articular car- 

 tilages. Speaking of that of the temporo- 

 maxillary articulation, he says, " its texture is 

 ligamento-cartilaginous."f 



The classification of fibro-cartilages adopted 

 by Meckel seems to me to be the best; he 

 arranges them under three classes: 1. Those 

 whose two surfaces are free wholly or at least 

 in great part, and whose edges are united to 

 the synovial capsules, the moveable fibro-car- 

 tilages of articulation. 2. Those which are 

 free by one of their surfaces, and which adhere 

 to bone or tendon by the other : these are 

 the fibro-cartilages of tendinous sheaths, or 

 those which limit the articular cavities, and may 

 Tse called jibro-cartilages of circumference or 

 cylindrical fibro-cartilages. 3. Those whose two 

 surfaces are adherent in their entire extent to 

 the bones between which they are placed. 



* De fabrica cartilaginum, Lipsise, 1747. 

 t Hunter on the Teeth. 



Of these classes the first and third and some 

 of those which come under the second belong 

 to the articulations. Their forms and structure 

 have already been described in the article 

 ARTICULATION. I may here, however, notice 

 the statement of Weber* in regard to the discs 

 interposed between the vertebrae, which have 

 been generally regarded as fibro-cartilaginous. 

 This anatomist denies that they exhibit any 

 intermixture of cartilaginous substance, and 

 considers that this is rendered manifest by 

 stretching the intervertebral substance, by which 

 it becomes reduced to a fibrous expansion 

 ( sehnighautige Masse) ; he consequently places 

 these intervertebral discs among the fibrous 

 tissues. There can be no doubt that the cir- 

 cumference of each disc is purely fibrous, and 

 that the concentric vertical lamellae of fibrous 

 tissue extend for some distance towards the 

 centre of the disc ; but I am at a loss to per- 

 ceive any resemblance to fibrous tissues in the 

 soft and elastic, and yielding substance which 

 forms the centre. It seems to me that this 

 texture can only be regarded as a modified 

 form of cartilage, differing in its want of 

 density from the ordinary cartilage, whether 

 permanent or temporary. The intervertebral 

 substance, however, to whatever texture it may 

 ultimately be decided to belong, does present 

 very striking differences from the other organs 

 which are placed among the fibro-cartilages. 



It is in the fibro-cartilages of the second 

 class that we see most uniformly the inter- 

 mixture of the fibrous and cartilaginous texture, 

 although here, likewise, the fibrous tissue pre- 

 dominates over the cartilaginous. 



The fibro-cartilages are remarkable for their 

 great flexibility, in virtue of which they are 

 enabled to resist fracture, and this property is 

 no doubt owing to the intermixture of fibrous 

 tissue; cartilaginous laminae, on the other hand, 

 are easily broken by bending, and many of 

 them exhibit a fibrous appearance on the surface 

 of the fracture, which, however, arises from 

 the irregular fracture and not from the existence 

 of fibres. Fibro-cartilages are of a dull white 

 colour and quite opaque; they have no perichon- 

 drium, but are either in immediate connexion 

 with bone, being inserted into it by their fibrous 

 bundles, or are covered by the synovial mem- 

 brane of the joint in which they are enclosed. 

 Their physical and vital properties are those 

 which belong to pure cartilage and to fibrous 

 tissue. Their force of cohesion is very great 

 and surpasses even that of bones. They are 

 more vascular than pure cartilage, but in the 

 natural state they admit very few vessels carry- 

 ing red blood. Bichat examined the fibro- 

 cartilages in an animal which died asphyxiated, 

 and found these organs not injected. The 

 remarkable manner in which fibro-cartilages 

 resist the influence of a compressing tumour, as 

 a pulsating aneurism, is well known; while by 

 such means the bodies of the vertebrae are 

 completely destroyed, the intervertebral discs 

 will remain quite uninjured. 



* Einige Beobachtungen iiber das Structur der 

 Knorpel und Faser-Knorpel, in Meckel's Archiv 

 for 1827. 



