46 ALUS. [Vol. XVIII. 



5. Nervus Trochlearis 237 



6. Nervus Abducens 237 



7. Trigemino-facial Complex 238 



8. Nervus Acusticus 272 



9. Nervus Glossopharyngeus 274 



10. Nervus Vagus 279 



1 1. Occipital and First Spinal Nerves 290 



Introduction. 



The present work on Scomber was begun in my laboratory, 

 in February, 1892, by Dr. J. Dewitz, and was continued, unfor- 

 tunately with frequent interruptions, until the spring of 1898. 

 Since then Mr. Jujiro Nomura has been engaged upon it, almost 

 continuously, until the present time, his work being the prepara- 

 tion of the drawings used for illustration and also the prepara- 

 tion of the dissections relating to the brain and to the roots and 

 apparent origins of the nerves. In all of Dr. Dewitz's dissections 

 the brain was so badly preserved that it disintegrated, leaving the 

 roots of the nerves detached. Those drawings that do not relate 

 to the brain are some of them copies of Dr. Dewitz's sketches; 

 others, those relating to the skull, are made from Dr. Dewitz's 

 preparations; while still others are from dissections prepared by 

 Mr. Nomura, guided by Dr. Dewitz's sketches. 



Soon after this work was begun by Dr. Dewitz, a similar work 

 was started, by other assistants I had engaged for the purpose, 

 on several other teleosts, my intention being to have the cranial 

 anatomy of some ten or fifteen teleosts and ganoids carefully in- 

 vestigated; my work on Amia having convinced me that, in all 

 questions relating to the morphology of the head, an exact knowl- 

 edge of the anatomy of the adult fish should precede any embryo- 

 logical investigation of it. This purely anatomical knowledge 

 could, I was well aware, be, to a great extent, derived from the 

 study, by sections, of advanced larvae, a method that is Certainly 

 much more enticing and perhaps much quicker. But dissections 

 of the adult must still often be referred to for completeness or for 

 control ; and, moreover, those dissections offer the great advan- 

 tage of the possibility of proper illustration. I had accordingly 

 decided to have the work first done on the adult, and then com- 



