252 



MANUAL OF HISTOLOGY. 



(more correctly speaking) of calcification in this case. Several of these 

 points, or bony nuclei as they have also been named, may occur in 

 one bone, without, however, necessarily springing up simultaneously. In 

 tubular bones the point of ossification of the diaphysis is mostly situated 

 in the interior of the middle ; and in double, flat, and short bones, in the 

 centre. Single bones have two or more such bony nuclei. From the 

 circumference of the latter the process of ossification now advances by 



degrees farther and far- 

 ther into the cartilage. 

 The latter, therefore, dis- 

 plays a difference of tex- 

 ture according to its 

 proximity to the bone 

 nucleus. 



In the examination of 

 such portions of cartilage 

 from the neighbourhood 

 of one of the latter, much 

 difficulty was formerly 

 experienced owing to an 

 opacity very difficult to 

 be overcome due to the 

 granules of lime. This 

 it is which has rendered 

 it so difficult to acquire 

 a correct knowledge oi 

 osteogenesis. We have, 

 however, rather recently 

 learned from H. Midler 

 a mode of overcoming this 

 obstacle by the employ- 

 ment of chromic acid, in 

 which the preparations 

 are placed. 



The deposition of the 

 calcium salts, further, dis- 

 plays much variety. In 



Rg. 242. Edge of ossification in a phalangfal cpiphvsis from a those places where the 

 calf, m vertical section; after If fitter. Above, the cartilage with 

 irregularly scattered cartilage capsules com aininglarge daughter 

 ells, a, sm.ill medullary spaces, appearing in some cases as 

 though closed, they are sketched empty ; 6, some of the latter 

 with medullary cells; c, residue of calcified cartilaginous 

 tissue; rf, larger medullary spaces, with thinner or thicker 

 osseous deposits on their walls, in the latter case it is laminated 



J 



cartilage cells lie close to- 

 gether, in small groups 

 or singly (fig. 237), they 

 are more completely 



tithTh e in^ p ^ enclosed in the lime 



T!L*> ne - ce " d ^P 81ted ..' n ? * a cavity partly filled up. ! ,i_ 



n 



^i^n^^w^ia^t^^i^oi^^^^^ granules than when ar- 

 ceuTKlTnt^ ranged in rows as 



bridges of the ground-substance often remain soft. 



147. 

 li uef 6 Calclfied . cartila S e commences now to undergo a rapid process of 



it is now traversed. This gives rise to the formation^of 8 nunLoL 

 medullary spaces. As a matter of course, the so much softer capsuTes are 



