521 



than any other nerve, those primitive characters which we find in 

 many of the lowliest Invertebrata ^), and, moreover, in most verte- 

 brates is of very 

 short extent, so that 

 its embryonic re- 

 lations undergo re- 

 latively slight distur- 

 bance in its growth 

 to the adult state, 

 it presents the most 

 favourable object for 

 the study of the 

 nature and mode of 

 origin of nerve fibres, 

 concerning which 

 there is so much 

 discordance in cur- 

 rent literature. 

 Hence, unlike the 

 cases of the motor 

 and general sensory 

 nerves, the complexity and 

 rapid modification of which 

 in the higher Vertebrata 

 make them unsuitable and 

 exceedingly difficult objects 

 to follow through all the 



Fig. 6. 

 Lateral Surface of cerebral Hemisphere 



1) This well known fact, 

 which the researches of Golgi, 

 Ramon y Cajal, Van Gehuch- 

 TEN, E,ETZius and Koelliker 

 elucidated, has been recently 

 emphasized by Eetzius, The 

 Principles of the Minute Struc- 

 ture of the Nervous System, 

 etc., Croonian Lecture, Proc. 

 Eoy. Soc, Sept. 23, 1908. 

 I discussed the morphological 

 significance of this fact in : 

 Notes on the Olfactory Centre, 

 Proceedings of the Inter- 

 colonial Med. Congr. of Austra- 

 lasia, 1897. 



Wall of 

 nasal Sac 



Fila olfactoria 



Formatio biilbaris 



