60 



THE ESSENTIALS OF HISTOLOGY. 



c 



FIG. 68. TBANS VERSE SECTION OP DECALCIFIED HUMAN TIBIA, PEOM NEAR THE 



SURFACE OF THE SHAFT. 



ii, H, Haversian canals, with their systems of concentric lamellse ; in all the rest of the figure 

 the lamellae are circumferential ; s, ordinary perforating fibres of Sharpey ; e, e, elastic 

 perforating fibres. Drawn under a power of about 150 diameters. 



FIG. 69. LAMELLA TORN OFF FROM A DECALCIFIED HUMAN PARIETAL BONE AT 



SOME DEPTH FROM THE SURFACE. (Sharpey.) 



a, lamellae, showing decussating fibres ; b, b, thicker part, where several lamellse are super- 

 posed ; c, c, perforating fibres ; the fibrils which compose them are not shown in the 

 figure. Apertures through which perforating fibres had passed are seen, especially in the 

 lower part, a, a, of the figure. Magnitude as seen under a power of 200, but not drawn to 

 a scale. (From a sketch by Allen Thomson.) 



