OSSIFICATIOX IX CARTILAGE. 



99 



to the newh'-formecl bone (c), which from its dark opaque aspect con- 

 trasts strongly with the cartilage, and tracing it towards their mutual 

 boundary, we see plainly the dark lines of ossification shooting up into 

 the clear spaces of the cartilage between the groups of corpuscles. The 

 earthy deposit, in fact, proceeds through the matrix, and affects also 

 those parts of the cartilage-capsules which form the circumference of a 

 group, so that the new osseous substance forms in the first instance 



Fig. 57. 



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Fig. 57. — Thin Longitvdixal Section op Ossifyixg Cartilage from the Humerus 



OF A FCETAL ShEEP. 



a, cartilage-cells uniformly diffused ; 6, cells nearer tlie boundary of the ossification, 

 collected into piles and inclosed in oblong areolce of the clear matrix ; c, dark lines of 

 ossification extending into the matrix and forming the i^riinary bony areolte. Magnified 

 about 70 diameters. 



Fig. 5S.- 



-Trassverse Section of the Ossifying Cartilage represented in 

 Fig. 57. 



I\Iade a little above r, along the surface of ossification, and including jiart of the new- 

 bone, magnified 70 diameters. The circular sections of the gi'oups of cells and of the 

 osseous areolae are seen ; and the dark bone extending into the clear intercellular matrix. 



oblong areola or loculi, which enclose the groups of cells. This is 

 further illustrated by a thin transverse section, carried nearly parallel 

 to the ossifying surface, and partly encroaching on it, so as to take off 

 a little of the bone along with the cartilage, as represented in fig. 58. 



