OBSERVATIONS ON THE CRANIAL NERVES OF SCYLLIUM. 499 
attempting to determine the homologies between the nerves of 
Scyllium and those of other vertebrates, preferring to wait 
until by the study of the development of other types we are 
enabled to bring forward positive evidence in support of our 
determinations. 
In conclusion, we would express the hope that, by working 
out the development of the roots and branches of the cranial 
nerves in a very typical vertebrate, and following these roots 
and branches through their subsequent changes up to their adult 
condition, we have rendered more practicable than has hitherto 
been the case comparisons between the descriptions of embryos 
and of the eorresponding adult animals, and have contributed 
something towards the establishment upon a firm basis of 
comparative neurology. 
