XIII.] 



BONE, OSSEOUS TISSUE, ETC. 



177 



their arrangement, as well as that of the lamellae (fig. 148). If a 

 canal be viewed carefully many fine dots will be seen in it. These 

 are the openings of the canal iculi. 



3. T.S. Decalcified Shaft of a Bone. The bone, cut into short 

 lengths, must be decalcified in picric acid or chromic and nitric 

 fluid, with the precautions laid down at p. 38. AVhen sufficiently 



FIG. 147. T.S. Shaft of Human Femur. 77. Haversian 



canals ; c. Lacunae with bone-corpuscles ; a. Lacuna) j,- IG> I4 8. L.S. Dense 

 with recurrent canaliculi ; s. Intermediary lamella? with (] r y bone, x 40. 



Sharpey's fibres, h; p. Large fibres of Sharpey in inter- 

 mediary lamella; ; I. Confluent lacunre. These Ranvier 

 supposes are bone-corpuscles and lacuna 1 undergoing 

 atrophy, x 300. 



soft ascertained by pricking it with a pin it is hardened in 

 alcohol in the usual way. Sections are best made by freezing. 



(i.) Stain a section in picro-carmine and mount it in glycerine- 

 jelly. Glycerine or Farrant's solution tends to make the prepara- 

 tion rather too transparent. 



(ii.) Place some sections in i per cent, osmic acid for twenty -four 

 hours and mount them in glycerine-jelly. 



(a.) (L) Observe the periosteum (fig. 149), embracing and 

 adherent to the bone. In the bone itself the lacunae, and especially 

 the canaliculi, are no longer black, and are not so visible as in the 

 non-decalcified bone. Each lacuna contains a highly refractive, 

 branched, nucleated, and stained corpuscle. 



Bone-Corpuscles. Observe their arrangement following that of 

 17 M 



