14 NECROSIS OF TISSUES. 



iificatlon we possess no reliable data, than to the fibres and 

 NETWORKS OF ELASTIC TISSUE. Their notoi'ious indifference to 

 cliemical reagents of all sorts is equally shown towards the 

 feebler agencies at work during mortification. The physician 

 <3onfidently anticipates that pulmonary gangrene will reveal itself 

 without the possibility of error by the appearance (among other 

 symptoms) of the elastic elements of the lung tissue in tlic 

 patient's sputa. Should the elastic fibres, howeverj become 

 involved in tlie destructive process, they begin by losing their 

 normal elasticity ; they become limp ; often, too, they swell, and 

 may ultimately be converted into a jelly-like substance. 



Those firmer and more compact fibrilhi^ of connective tissue 

 of v\'hich the tendons are composed, and which also occur in 

 fibrous membranes (dura mater, tendinous, muscular and arterial 

 sheaths, periosteum), behave like the fibres of yellow clastic tissue. 

 The first indication which these structures (I refer more par- 

 ticularly to the tendons) present of l)eing involved in moist 

 o-ano-rene, consists in an unravelling of the parallel bundles of 

 fibres from one another ; this must be ascribed chiefly to soften- 

 in o- and disorfranisation of the connective tissue intercalated 

 between them, in which the vessels run. At a later stage, how- 

 ever, the so-called secondarj- and tertiary fibrillar are separated 

 from one another, and the tendon is converted into a shagiiy 

 mass of fibres, which bears the same relation to its normal struc- 

 ture that carded hemp bears to a well-twisted rope. Even in 

 this stage, however, the tendon, as a whole, is not easily torn ; 

 it is only at a much later period that the fibres begin to break 

 up into single granular and beaded strips ; these, in their turn, 

 melt away into molecules of minute size, and so become in- 

 visible. 



§ 20. Cartilage is one of the most indestructible tissues of 

 the body. The chemical composition of the inter-cellular sub- 

 stance is very stable, and this, perhaps, is the main reason why 

 large pieces of cartilage, e.g, detached articular surfjices, resist 

 necrotic disintegration for long periods of time. When this 

 nltimately prevails, it mostly takes the form of a gradual peri- 

 pheric liquefaction, during which the cartilage becomes trans- 

 parent and assumes a reddish tinge. This colour cannot certainly 

 he supposed to be due in all cases to imbibition of the red 

 <?olouring matter of the blood ; this hypothesis is discredited by 



