VIII.] CELLULAR AND HYALINE CARTILAGE. 14? 



II. Hyaline Cartilage. This consists of cells or corpuscles em- 

 bedded in a hyaline matrix. 



2. Cartilage of Newt (L and H). Snip off a small piece of the 

 thin cartilage of the sternum of a freshly-killed newt, and with a 

 scalpel scrape away any librous tissue or 



muscle adhering to it. Mount it in normal > 



saline solution or J per cent, solution of alum. \ 



(a.)Observe a homogeneous matrix (fig. no, 

 m\ like ground glass, in which are embedded m-~-^ 

 here and there cartilage-cells or corpuscles 

 ('). The matrix is comparatively small in 

 amount, and hyaline. v'Cy 



(?>.) Each corpuscle consists of a spherical 

 mass of transparent, finely-granular cell-sub- , k - 

 stance (c). Sometimes the protoplasm con- *tftS. 5 iSSix?* 

 tains refractile granules of oil, and in it is Body of cartilage-cell ; 



, , , . , , , , , , n. Nucleus, x 250. 



placed a spherical, clear, granular nucleus (n), 



Near the margin of the preparation may be seen cavities or capsules 

 from which the cell-contents have fallen out ; others where the 

 cell-contents have shrunk from their capsule ; while at other places 

 the cells completely fill the spaces in which they lie. On focussing 

 through the thickness of the tissue, the cells are seen to be two or 

 more layers deep, i.e., in a section of moderate thickness they lie in 

 several planes. The cells may lie singly or in groups. 



3. Effect of Acetic Acid (H). Irrigate with a 2 percent, solution 

 of acetic acid. 



(a. ) Observe that the nucleus becomes more distinct and granular, 

 the cell-contents clearer, and the cell shrinks from its capsule, so that 

 a space is left between the capsule and the irregular shrunken cell- 

 contents. 



4. Action of Gold Chloride (H). Mount in Farrant's solution 

 a section of articular cartilage from the head of the femur of a 

 fivshly-killed frog which has been stained by the gold chloride 

 method (p. 78). If the gold be reduced by formic acid the bone is 

 thereby softened, so that both bone and cartilage can be cut together 

 in a freezing microtome. 



(a.) Observe the matrix faintly stained, and the corpuscles or 

 cell-contents, but not nucleus, stained of a purple hue. The cell- 

 contents have shrunk very little. Here and there an empty 

 cartilage-capsule may be seen. The gold chloride has a special 

 affinity for the protoplasm of the cartilage-cells, so that they stand 

 out distinctly in contrast to the less-stained matrix in which they 

 lie embedded. This preparation represents, as it were, the " positive 

 picture," in contrast to that obtained by the use of silver nitrate, 

 \vhii-h yields the "negative picture" (p. 77). 



