22 



ANATOMY OF VERTEBRATES. 



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

 the resi)ective vertebrate classes. ' In the concentric laminje sur- 



11 



Plasmatic canals in a fislt-bnnc. n transverse, b longitudinal, section 

 of vascular canal 1.T0MES, cl.) 



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



arranged concentrically, between the lamina;, with the lono- axis 



12 





^ 



jS> 



& 



Forms of bone-cells in ^^n,on ami Boa Constrictor. Cb 



in the direction of the circular line of tlie plate. Iklost of the 

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



