104 THE TISSUES 



derm. It is at first wholly cellular. Each cell forms a capsule around 

 itself, and by blending of these capsules are formed the first elements 

 of the intercellular matrix. This increases in quantity and assumes 

 the structural characteristics of one of the forms of cartilage. The 

 white fibres of fibro-cartilage and the yellow fibres of elastic cartilage 

 develop in the same manner as in fibrillar and elastic tissue. 



Fig. 50. — Fibrous Cartilage from Dog's Intervertebral Disc. X350. (Technic 3, 

 below.) Groups of cartilage cells in matrix of fibrillar connective tissue. 



TECHNIC 



(i) Hyaline Cartilage. — Remove a frog's femur and immediately immerse the 

 head in saturated aqueous solution of picric acid. Cut sections tangential to the 

 rounded head, keeping knife and bone wet with the picric acid solution. As bone 

 must be cut, a special razor kept for the purpose should be used. Cut sections as 

 thin as possible. The first sections consist wholly of cartilage. As bone is 

 reached, the cartilage is confined to a ring around the bone. Mount in the 

 picric-acid solution, cementing the cover-glass immediately. 



(2) Elastic Cartilage. — Remove a piece of cartilage from the ear and fix in 

 formalin-Muller's fluid (technic 6, p. yj. Stain sections strongly with hema- 

 toxylin, followed by picro-acid-fuchsin (technic 3, p. 21). Clear in carbol-xylol 

 and mount in balsam. The capsules around the cartilage cells are thick and, as 

 they usually retain some haematoxylin, can be readily seen. Note also the 

 flattened cartilage cells near the surface, and the perichondrium. 



(3) Fibro-cartilage. — Fix pieces of an intervertebral disc in formalin-Muller's 

 fluid. Sections are stained either with haematoxylin-eosin or with hasmato.xy- 

 lin-picro-acid-fuchsin and mounted in balsam. 



BONE 



Bone is a form of connective tissue in which the matrix is ren- 

 dered hard by the deposition in it of inorganic matter, chiefly the 



