Connective Tissues. 



27 



tissue cells, chromatophores, and partly to the presence of 

 pigment granules in epithelium. The absence of pigmentation in 

 animals belonging to species normally colored — albinism — is 

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

 coloration of the eyes, the 

 latter being due to the cir- 

 cumstance that the blood- 

 w ssels of the vascular tunic 

 are not concealed by pigment. 



s 



& 



m. 



c.c. 



<3P 



B. Skeletal Tissues. 



.1. 



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

 lacuna : m., matrix. 



•. O, 



7 <£>*-[ ?-'.\^; 



v 



The skeletal tissues are 

 -olid forms of connective 

 tissue which, on account of 



their more permanent shape, are better adapted to form a support 

 for the body. They are of two kind- cartilage and bone. 



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

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

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

 cells are distributed singlv, 

 or more often in groups ot 

 two to four, each group being 

 contained in a small oval 

 space, the cartilage lacuna. 

 The size of the spaces, and 

 also their distance apart, is 

 subject to great variation. 

 The addition of fibrous ele- 

 ments, usually of white fibres, 

 produces a modification 

 known as fibrocartilage. 

 While fibro-cartilage occurs 

 in certain situations, as in the 



symphysis of the pelvis, or in connection with the interarticular 

 menisci and at the capsular margins of the joints. 



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

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





.he. 

 -i.L. 



Fig. o. Intramembranous bone; from a ground 

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

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

 lamellae; L.I., interstitial lamellae; lac, lacuna. 



