THE OSSEOUS SYSTEM. 



317 



The formation of the bone-corpuscles, as they arc termed, 

 may be traced perhaps more clearly in the symphysis than 

 anywhere else, except in rachitic bone (fig. 1.24). For at its 

 osseous borders there are always to be found, either half 

 projecting from, or entirely lodged in, the cartilage, isolated, 

 nucleated bone-corpuscles or cells, with homogeneous, and (from 

 calcareous salts) granular walls, measuring 0012 — 0-016"', 

 with respect to which, from their development and from the 

 consideration of the contiguous cartilage-cells, all of which 

 present more or less thickened walls and rudiments of cal- 

 careous deposits, not the smallest doubt can be entertained. 

 Well characterised, half and wholly ossified parent cells of the 

 same kind, with two secondary cells, and measuring 0*015 — 



Fig. 123. 



0'03"', up to some including ten or twenty secondary cells, and 

 having a length of 005'", may be distinctly noticed in almost 

 every preparation. 



The sacro-iliac synchondrosis is effected by means of a 

 flattened layer of cartilage, | — 1£'" in thickness, which is 

 closely attached to the auricular surfaces of the corresponding 

 bones, between which it is interposed. The cartilage-cells 

 close to the bone are flattened, with their surfaces directed 



Fig. 123. Cartilaginous border, towards the cartilage of the symphysis in .Man, 

 x 350 diam.: a, cartilage cells with thickened walls; b, the same undergoing ossifi- 

 cation; c, cells nearly ossified, with homogeneous walls free in the matrix of the car- 

 tilage; d, similar cells with calcareous granules; e, ossified cells at the border of the 

 matrix of the bone containing calcareous granules, and half projecting from it. 



