VASCULAR CANALS OF BONES. 



there is usually no marrow contained in these narrow 

 channels ; they should properly be called vascular canals ; 

 still the other terra is so universally received, that it is 

 even employed in cases where the wall of the vessel is in 

 immediate contact with the internal surface of the cavity. 

 Immediately surrounding these canals we see a series of 

 peculiar structures ; oblong or roundish bodies which 

 usually appear black when the object is not fully brought 

 into focus, and are provided with jaggs or processes. 

 They used to be called bone-corpuscles, and their pro- 

 cesses bone-canals (canaliculi ossei) ; and as the view 

 was originally entertained that the calcareous matter 

 was really deposited in them, and that the dark appear- 

 ance which they usually present when viewed by trans- 

 mitted light resulted from the presence of this matter, 

 the canals were also termed canaliculi chalicophori, a 

 name which has now been altogether abandoned, because 

 convincing proofs have been obtained that, so far from 

 being contained in them, the lime is, on the contrary, 

 diffused throughout the homogeneous basis-substance 

 which lies between them. 



As soon as this discovery was made, that, namely, the 

 distribution of the lime in the osseous tissue took place 

 in a manner just the reverse of that in which it had been 

 supposed it did, the other extreme was immediately run 

 into, and for the name of bone-corpuscles that of bone- 

 cavities (lacunae) was substituted, and it was assumed 

 that bone contained nothing but a series of empty cavi- 

 ties and canals, which were indeed penetrated by a 

 fluid, but still were really nothing more than fissures in 

 the bone. Some few observers indeed actually called 

 them bone fissures Now I have endeavoured to demon- 

 strate in various manners that they are real corpuscles, 

 and not mere cavities in a dense basis-tissue, but struc- 

 tures provided with special walls and boundaries of their 



