4 PRACTICAL ANATOMY. 



here and there with the processes of the cell in the 

 adjoining lacuna. The canaliculi are extremely fine 

 tubules, which, as a rule, do not exceed 3 ^o^ inch in 

 length, and which measure from 2T^ 7 inch to T 2T 77 

 inch in diameter. If a bone is macerated in dilute nitric 

 acid, the mineral matter it contains is dissolved out, the 

 bone loses its rigidity, and becomes pliable and compres- 

 sible, although it retains its original form. Any long, 



FIG. 1. LACUNAE AND CANAMCULI. 

 (The lacunas contain the bone-corpuscles.) 



thin bone thus treated can be tied in a knot. If a sec- 

 tion is made of a macerated bone, it is found to retain 

 its grosser histological characters, but the canaliculi are 

 indistinct and not readily discerned. There are, however, 

 some further points clearly brought into view. The 

 fibrous structure of the bone becomes apparent, and, as 

 the bone was originally molded in nbro-cartilage, the 

 fibrous elements are seen forming primary and secondary 

 lamellae. A primary lamella is the arrangement of the 



