BONE. 43 
ii. The cartilage cells: imbedded in the matrix: 
each cell nucleated, and occupying a cavity or 
lacuna in the matrix. In places the cells are in 
groups of twos or fours owing to recent division. 
Wash the specimen thoroughly in water: stain with hema- 
toxylin, and mount as a permanent preparation in glycerine: 
examine with high power, and note that 
iii, The cell nuclei are stained deeply, and the matrix 
very slightly: the layer of matrix immediately 
surrounding each cell—the capsule—stains more 
deeply than the other parts. 
II. Articular cartilage. Forms caps covering the ends of 
those bones which fit together to form moveable joints : 
these caps act as elastic cushions to break the force 
of shocks. 
Mount in balsam prepared section of articular cartilage from 
the head of the femur, the section being made perpendicular to the 
articular surface: exanune with low and high powers: note :— 
i. The matrix: hyaline or faintly granular. 
ii, The cartilage cells. Towards the free surface the 
cells and cell groups become gradually flattened 
and arranged parallel to the surface. 
F, Bone. 
Bone consists of a dense fibrillar intercellular matrix, in 
which are imbedded cells which lie in cavities connected with 
one another by fine branching canals. The matrix is richly 
impregnated with inorganic salts, chiefly phosphate and car- 
bonate of lime, which form about two-thirds by weight of the 
substance of the bone and give it its great hardness and strength. 
The matrix, with its contained bone-cells, is arranged in con- 
centric layers or lamellz, formed in succession one within 
another around central canals in which lie the bloodvessels, 
which penetraté the bone in great numbers. A bloodvessel 
with its surrounding layers of matrix and cells is spoken of as a 
Haversian system, 
1, Huxamine with both low and high powers prepared trans- 
verse sections of a long bone: note -— 
