THE OLFACTORY NERVE, THE NERVUS TERMINALIS 

 AND THE PRE-OPTIC SYMPATHETIC SYSTEM IN 

 AMI A CALVA, L. 



CHARLES BROOKOVER 



From the Anatomical Laboratory of the University of Chicago 

 WITH THIRTY-FIVE FIGURES 



Material and Methods 50 



Historical Sketch 52 



Embryological Development of the Olfactory Organ in Amia 57 



Adult Structures of the Olfactory Organ in Amia 77 



Central Relations of the Nervus Terminalis in Amia 83 



Intra-cranial Sympathetic System Posterior to the Nervus Terminalis in 



Amia 92 



The Nervus Terminalis of Lepidosteus and Teleosts 106 



Discussion and Theoretical Conclusions 108 



Summary of Results 113 



There are two main reasons why Amia was selected for a study 

 of its nervous system. It is an archaic form likely to show inter- 

 esting relationships with the sharks and other lower vertebrates. 

 In the second place, it is relatively abundant in the region where 

 the work was first undertaken, so that it could be procured in 

 numbers to satisfy the demands of the neurological methods. 

 It was our original intention to describe the anterior part of the 

 central nervous system and thus supplement the work done by 

 Kingsbury ('97), on the medulla oblongata and by Allis ('97) on 

 the peripheral nerves of Amia, but when it was found that there 

 are large numbers of ganglionic nerve cells among the olfactory 

 fibers in the adult nasal capsules and that these cells are derived 

 from the ganglion which Allis described in the young Amia, it 

 was thought best to study first the peripheral olfactory appara- 

 tus. The work on the central nervous system has been deferred 

 for a later paper. The present article includes a study of the em- 



