22 



ANATOMY OF VERTEBRATES. 



degree, characterise, by their shape and size, the osseous tissue of 

 the respective vertebrate classes. In the concentric laminae sur- 



11 



Plasrnatic canals in a fish-bone, a transverse, 6 longitudinal, section 

 of vascular canal (.TOMES, CL.) 



rounding the vascular canal, fig. 15, a, a, the bone-cells are 

 arranged concentrically, between the laminae, with the long axis 



12 13 







Forms of bone-cells in Python and Boa Constrictor. CL. 



in the direction of the circular line of the plate. Most of the 

 plasmatic tubes continued from the bone-cells pierce the plates at 



