EXPLANATION OF THE PLATES. 189 



of the amorphous fundamental substance of the line are to be 

 seen: 1, the stellate or branching bone-cells (lacunae); their 

 branches or prolongations (2) in the shape of canaliculi, anasto- 

 mosing with each other so as to form a network by which a 

 communication is established between the corpuscles themselves, 

 and also with the Haversian canals 3, or with the interior cavi- 

 ties of the bone. 



FIG. V. Same section seen with a magnifying power of 

 eighty diameters. The bone-corpuscles (lacunae), in the shape 

 of minute elongated black spots, are seen to be grouped in con- 

 centric circles around the Haversian canals (1). 



,' r l ; (L'o 



PLATE VI. 



BONE, continued. 



FIG. I. Longitudinal section of the shaft of the femur 



(80 diameters). 1, Longitudinal Haversian canals; 2, trans- 

 verse anastomotic canal ; 3, confluence of several canals. 



FIG. II. Longitudinal section of the condyles of the 

 femur (in a newly born infant. Magnifying power of 180 

 diameters). 1, Line of junction of the cartilage with the bone. 

 Above this line the cells of the cartilage are seen grouped in 

 parallel rows. Their nuclei (2) deeply shaded and presenting 

 jagged edges. Below this same line the cartilage is seen, infil- 

 trated with earthy salts and in process of ossification. 



FIG. III. Section of cartilage taken from same femur y^th 

 of an inch beyond the newly ossified portion. 1, Fundamental 

 substance, entirely transparent ; 2, limit of the capsule ; 3, limit 

 of the cell ; 4, nucleus assuming a branching character. 



FIG. IV. Formation of marrow and of medullary cavi- 

 ties in newly ossified bone (from same femur). 1, Fundamen- 

 tal substance infiltrated at certain points with free fat 2 ; 3, 

 capsule of cartilage cells ; 4, a parent cell full of young cells ; 

 5, unbroken partition between two capsules ; 6, cavity resulting 

 from the fusion of several cells ; it contains young cells (cells of 



