Connective Tissues. 



27 



3sue cells, chromatophores, and partly to the presence of 

 gment granules in epithelium. The absence of pigmentation in 

 limals belonging to species normally colored — albinism — is 

 dicated by the white coloration of the hair and by the pink 

 )loration of the eyes, the 

 tter being due to the cir- 

 imstance that the blood- 

 jssels of. the vascular tunic 

 ■e not concealed by pigment. 



B. Skeletal Tissues. 





.1. 



Fig. 8. Hyaline cartilage; c.c, cartilage cell; 

 1., lacuna; m., matrix. 



The skeletal tissues are 

 )lid forms of connective 

 ssue which, on account of 

 leir more permanent shape, are better adapted to form a support: 

 ir the body. They are of two kinds — cartilage and bone. 



Simple or hyaline cartilage (Fig. 8) is a semi-solid and some- 

 hat resilient material of a bluish or pearly coloration. It consists 

 ' a homogeneous matrix in which the cells are imbedded. The 

 ;lls are distributed singly, 

 ■ more often in groups of 

 vo to four, each group being 

 mtained in a small oval 

 )ace, the cartilage lacuna. 

 he size of the spaces, and 

 so their distance apart, is 

 ibject to great variation, 

 he addition of fibrous ele- 

 lents, usually of white fibres, 

 reduces a modification 

 tiown as fibrocartilage. 

 ^hile fibro-cartilage occurs 

 i certain situations, as in the 



rmphysis of the pelvis, or in connection with the interarticular 

 enisci and at the capsular margins of the joints. 



In the adult skeleton cartilage is present only in small amount. 

 : forms the articular surfaces of joints, the ventral portions or 



Fig. 9. Intramembranous bone; from a ground 

 section of the rabbit's femur: c.l., -circumferential 

 lamellae; h.c Haversian canal; h.l., Haversian 

 lamellae; i.l., interstitial lamellae; lac, lacuna. 



