CARTILAGE. 



703 



Cartilage forms the entire skeleton in some kinds of 

 fishes, the Skate, Lamprey, &c. j and it is nourished with- 



ie=l«ess?^- 



1 2 



Fig. 333. 



1, Cartilage from Rabbit's ear, showing large cells embedded in a fibrous 

 matrix. 2, Cartilage from Human ribs, with cells in groups, each having a 

 granular nucleus. (Magnified 200 diameters.) 



out coming into direct contact with 

 therefore it is said to be non-vascula 

 derived b3'imbitionfrom i\\Q surround- 

 ing blood-vessels. When examined 

 microscopically, the simplest form of 

 cartilage is seen to resemble in a 

 stiiking manner the cellular tissue of 

 vegetables ; it consists of an aggre- 

 gation of cells of a spherical or oval 

 form, capable in some cases of being 

 separated from each other, and every 

 cell having a nucleus, with a nucleolus 

 in its interior. In figs. 332, 333, and 

 334, we have varieties of this structure. 

 In the more highly organized scale 

 of animals, a strong fibrous capsule, 

 or sheath, surrounds the cartilage- 

 cells; some of the fibres dip in amongst 

 the cells, and bind them firmly 

 together. In those inhabitants of the 

 water, the Eay and Shark, the entire 

 tilaginous, the cell is imbedded in a 



the blood-vessels, 

 ■ ; nourishment is 





Fig. 334. — Cartilarie from 

 the Cuttle-fish, sliowing 

 stellate form of cells. 



skeleton being car- 

 matrix, which may 



