38 THE SIMPLE TISSUES. 



and in the recent state calcareous. An irregular line separates 

 the cartilage from the subjacent bone. Shallow depressions, 

 recesses communicating with the medullary cavity and containing 

 blood vessels, are visible ; these become filled later with boss-like 

 deposits of bone. 



White fibro-cartilage. S. Intervertebral disc (p. 11, c. G., s. 19, 

 m. F.). (L) The arrangement into concentric layers is most 

 distinct at the periphery. (H) A gelatinous, fibrous-looking 

 material, with scattered small clusters of cells in thin envelopes. 

 In the centre of the disc, if included in the section, is seen 

 an agglomeration of various sized cells with distinct capsules, 

 and little, if any, interstitial substance. This is a relic of 

 the notochord, and the nearest approach to parenchymatous 

 cartilage in the human body. 



Interarticular cartilages have the same structure, but the 

 laminar arrangement is not present, the fibres of the matrix 

 being more interlaced. 



Spongy, yelloiv or elastic cartilage. T.S. Epiglottis (p. 3, c. G., 

 s. 19, m. F.). (L) Externally stratified squamous epithelium 

 under this connective tissue, pink, in it are mucous glands. The 

 cartilage, surrounded by fibrous perichondrium, is perforated 

 with large apertures filled with fibrous tissue containing blood 

 vessels. The cartilage is tinted yellow. At its edges (//) 

 observe the elastic fibres passing from perichondrium to matrix, 

 and which beginning as fine filaments quickly further in pass 

 into a close, spongy structure enclosing the cell spaces. These 

 contain the nucleated cartilage cells. 



Arytenoid cartilage, (p. 11, c. G., s. 19, m. F.) (L) Fibrous 

 nature of the tip. (//) The matrix of the cornu is yellow 

 fibro-, passing into the hyaline cartilage towards the base. 



