162 



ZOOLOGY 



SECT. 



It will be observed that the system of neuromast organs (lateral 

 line and ampullary organs) are supplied by nerve-fibres which pass 

 out in various branches of the facial and in the vagus (lateralis) : all 

 these fibres originate in a centre in the medulla, the a cusiico- lateral 

 centre, common to them and the fibres of the auditory nerve. 



The spinal cord is a cylindrical cord which extends from the 

 foramen magnum, where it is continuous with the hind-brain, 

 backwards throughout the length of the neural canal, enclosed by 

 the neural arches of the vertebra3. As in the Craniata in general 

 (see p. 98), it has dorsal and ventral longitudinal fissures and 



