431 



If a section of the bone is dried in the air and then mounted 

 in balsam or glycerine, the lacunae and canaliculi appear in trans- 

 mitted light, black, and in reflected light, silvery-white, showing that 

 by the drying up of their semi-fluid contents, they have become filled 

 with air. Old fragments of bone that have dried in the sun for an 

 indefinite period, when softened and sectioned, show the same 

 structure. Boiling sections of fresh bone in caustic potash dissolves 

 the granular contents of the lacunae, but does not otherwise affect 

 them. 



The successful staining of the alcoholic material is a matter of 

 some difficulty. The stain will not enter the lacunae except they be 

 actually opened up by the knife or lie very close to the surface of 

 the section. Borax carmine and Kleinenberg's or Grenacher's 

 haematoxylin have given the best results. If the sections are trans- 

 ferred quickly from the stain to balsam, many of the lacunae and 



Fig. 2. 



O..C 





canaliculi appear intensely colored as though injected with the stain, 

 as they really are, the fluid seemingly entering by capillarity and 

 afterwards running out slowly. When the sections are well washed 

 this color usually disappears from the canaliculi, but even after 

 long washing with acidulated alcohol, some of the lacunae show a 

 characteristic color due to the presence of a faintly stained, granular 

 substance. In the most successful preparations, especially those 



