11 IK OSSKors SYSTK.M. 



QEQ 



of perfect bone. According to all appearance, the primordial 



earthy granules or particles become gradually fused together, 

 and thus impregnate the whole tissue of the matrix of the car- 

 tilage, instead of, as Fig. 132. 

 before, separate por- ' ~ " ;\ 

 tions, and thenceforth 

 disappear as isolated, 

 distinguishable par- 

 ticles. 



With respect to 

 the formation of the 

 bone-cells, I believe, 

 that owing to the 

 discovery of an ex- 

 cellent subject for 

 their observation, viz. 

 rachitic bone, I have 

 put the matter, as re- 

 gards the most essen- 

 tial particulars, in a 

 clear point of view. 

 The bone-cells are 

 formed,— as Schwann 

 thought possible, and 

 llcnle supposed, from 

 analogy with the lig- 

 nified vegetable cell 

 with pores or dotted 

 canals, — from the cartilage-cells, by the thickening of their wall, 

 with the simultaneous formation of canalicular vacuities in it, 

 and its ossification. In the ossifying shaft of a rickety bone 

 (fig. 132) the morphology of this process may be most beauti- 

 fully observed. If the rows of cartilage-cells of the ossifying 



Fig. 132. From the ossifying border of the condyle of the femur of a rachitic 

 child, two years old, x 300 diarn.: a, cartilage cells, simple and parent cells in scries ; 

 b, more homogeneous; c, striated matrix between them; d, cartilage-cells at the 

 commencement of their transformation into bone-cells ; e, the same further advanced, 

 with very much thickened walls, indication of canaliculi, commencing deposition of 

 calcareous matter in the walls, whence their darker colour, though still with distinct 

 nuclei ; /, bone-cells still more developed and more ossified, in an equally ossified 

 matrix. 



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