314 



THE TISSUES. 



Fig. 202. 



Section of fibro-cartilage ; showing disposition of car- 

 tilage-cells in areolae of white fibrous tissue. 



Fig. 203. 



boiling. 2. Those with a fibrous intercellular substance; either- 

 white fibrous tissue, or elastic tissue. The latter are termed fibre- 

 cartilage, in case the intercellular substance is white fibrous tissue 



(Fig. 202); and reticular carti- 

 lage (or yellow cartilage), if it 

 be the elastic tissue. This 

 last form of fibro-cartilage is 

 found in the external ear, and 

 the cartilaginous portion of 

 the Eustachian tube, and in 

 the epiglottis. The cartilages 

 of Santorini and Wrisberg 

 (of the larynx), and that on 

 the condyle of the lower jaw, 

 are of this class. The struc- 

 ture of the reticulated carti- 

 lage is shown by Fig. 203. 

 Hoppe found that the reticu- 

 lated cartilages yield chon- 

 drine in small quantity on 

 boiling. He, however, main- 

 tains that this substance is not 

 derived from the cells, nor 

 from the elastic fibres, but 

 from athird(achondrine yield- 

 ing) substance, surrounding 

 the cells. Indeed, from his 

 conclusions in regard to carti- 

 lage-cells, he was led to the 

 axiom that cell-membranes 

 and cell-contents never consist of gelatigenous substance (osteine or 

 cartilageine) ; and can never be metamorphosed into it. 



Fibro-cartilage yields only glutin, since the white fibrous tissue 

 constitutes its intercellular substance. All the intra-articular fibro- 

 cartilages are of this kind. Its structure has been shown by Fig. 

 202. 



True Hyaline Cartilage. 



True cartilage consists of (1), cartilage-cells, and (2) a hyaline (or 

 usually granular) homogeneous substance (p. 108). 



Kcticulated cartilage; human epiglottis. Magnified 

 350 diameters. (Kulliker.) 



