ENAMEL 69 



the opposite side, in any sections examined. In longitu- 

 dinal section the prisms appear wavy, and in many parts 

 show grooves and feathered margins (fig. 27). 



Fig. 28 shows very distinctly the actual arrangement of 

 these double concave prisms in the Elephant. It was 

 photographed at a crack in the enamel, and the prisms are 

 seen at the same time in both longitudinal and transverse 

 section : the fringed margins and little shining points, 

 apparently due to the broken connecting bridges, are also 



FIG. 27. Enamel of molar of Indian Elephant. Longitudinal section 

 showing grooves, &c. ( x 500.) 



visible. From this photograph and from many preparations 

 it would appear that the prisms of the enamel are arranged, 

 not in direct lines from the dentine, but that independently 

 of all their curves and intercrossing they maintain a slope 

 towards the dentine which it is very difficult to follow out 

 or define. 



The connecting bridges in the Elephant are well shown 

 in fig. 29 in longitudinal section, and in transverse section 

 in Plate III, fig. 6. These processes are seen to pass across 

 the interprismatic substance and form connexions between 

 neighbouring columns. In the longitudinal view it is seen 

 that the connecting processes are somewhat irregular in 



