Herrick, Cranial Naves of Bony Fishes. 163 



system. The acustico-lateral system receives fibers from the 

 ear and lateral line organs and no others. These fibers all ter- 

 minate together in the tuberculum acusticum. 



In the cranial nerves the motor fibers for the unstriated 

 visceral musculature (with sympathetic connections?) are, as in 

 the trunk, very small, while those for the striated visceral mus- 

 culature of the branchial arches and for the somatic eye-muscles 

 are large. The general cutaneous fibers are small or medium, 

 the communis fibers are all very sm;\ll, and of the acustico-lat- 

 eral fibers those from the lateral line organs are for the most 

 part very large, while the auditory fibers are of medium size. 



The accompanying diagram exhibits the relations of the 

 sensory components in the cranial nerves of Menidia and some 

 of the more important points are reviewed in the following 

 summary. 



1. The ramus medius (r. lateralis of authors) of the spinal 

 nerves usually anastomoses with a twig of the n. lateralis vagi ; 

 but in all cases the spinal fibers go to the skin around the lateral 

 line, and never to a lateral line organ. 



2. The first spinal is obviously a fusion of two segmental 

 nerves, possibly of more than two. 



3. ThQ vagiis nen>e coni?ims general cntaneoits fibers (rami 

 cutanei dorsales), which have a special ganglion (jugular g. of 

 Shore and Strong) and which terminate in the spinal V tract. 



4. The vagal lobe is mainly, at least, the terminal nucleus 

 for visceral sensory fibers and hence is to be regarded as the 

 continuation into the head of the "intermediate zone" of the 

 spinal cord, rather than of the dorsal horn, as some have main- 

 tained. These fibers, which will be termed conininnis fibers, 

 are in part general visceral sensory fibers from mucous surfaces 

 and in part fibers from more highly specialized organs — taste 

 buds etc. 



5. The nucleus ambiguus, giving rise to the motor root of 

 the vagtis, has been specialized away from the general viscero- 

 motor center in correlation with the development of the striated 

 visceral musculature of the branchial arches. The central ner- 



