460 LECTURE XVIII. 



real bone, it is necessary that the cavity in which every 

 cartilage -cell lies, be converted into the well-known, 

 radiated, jagged bone-cavity [lacuna]. This process is 

 so extremely difficult to obtain a sight of, because on 

 making sections the masses of lime crumble away before 

 the knife, and furnish debris within which it is impossi- 

 ble to see well what really is present. In this circum- 

 stance you must seek for an explanation of the fact, that 

 up to the present time there are still, and probably still 

 will be for several j^ears, continual disputes with regard 

 to the mode of origin of bone corpuscles. I hold that 

 view to be correct, according to which the bone-cor- 

 puscles* in certain places directly originate out of the 

 the cartilage-corpuscles, and indeed in this way, that in 

 the first place the cavity of the capsule which invests 

 the cartilage-cell, becomes narrower, manifestly because 

 fresh capsular matter is deposited on the inside. But 

 in proportion as this takes place, the inner border of the 

 capsular cavity begins to assume a distinctly indented ap- 

 pearancef (Fig. 133, c') and the space occupied by the 

 original cell is thereby considerably diminished. In rare 



* Cartilage-corpuscle = capsule -j- cartilage-cell; bone-corpuscle = bone-cell. 

 Transl. 



f The lacunae may be said really to have no existence in living bone (or osteoid 

 tissue) ; they are merely the gaps (holes) in the intercellular substance in which 

 the bone- (or osteoid-) cells lie, and are normally so entirely filled by these cells, 

 that it is impossible to give the outlines of both in a drawing. The outline of the 

 cell is the outline of the lacuna. Who, in drawing a deal-board, would ever think 

 of giving a second contour to every knot, in order to represent the outline of the 

 gap which would result from the falling out of the knot ! Hence Authors have 

 come to speak of the nuclei of lacunae, whereby of course they mean the nuclei of 

 the cells which fill the lacunas, but which, thanks to the deeply rooted but errone- 

 ous impression left upon their minds by microscopical sections of macerated bone, 

 they have failed to recognize, or have not even sought for, taking for granted they 

 had lacunae before them. In the preparation of sections, however, the cells frequently 

 shrink, no that an interval is left between theui and the walls of the lacunaa. 



What is here said of the lacunae of course equally applies to the canaliculi. 

 Both represent the margins of the calcified intercellular substance, where it comes 

 into contact with the bone-cells and their processes. Based upon MS. Notes by tht 

 Author. 



