Art. II.] 



Herrick, Gustatory Paths m Fishes. 



83 



ial consists of serial sections of ten adult brains cut in the three 

 conventional planes and stained with Delafield's haematoxylin 

 and by the methods of Weigert and Weigert-Pal, together 

 with serial sections of about lOO younger brains prepared by 

 the method of Golgi and cut in various planes. 



The vagal lobe of the cat fish is essentially similar to that 

 of most other teleosts. The general relations as seen in tran- 

 sections stained by Delafield's haematoxylin are shown in 

 Fig. 26. The lobe is crowded with numerous small nerve cells, 



dors- sec. neurones 

 intrinsic neurones 

 superfic- root of X 

 lat. sec. neurones 

 deep root of X 



nuc- intermedius X 

 spinal V tract 

 desc. sec. VII tract 

 asc. sec. gust, tract 

 motor root of X 



ventral cornu 



Fig. 26. Transverse section through the vagal lobes of a large adult of 

 Ictalurus punctatus (Raf.). Drawn from a haematoxylin preparation. X 16. 



/"./.;«., fasciculus longitudinalis medialis ; ti.amb., nucleus ambiguus ; j.r.^., 

 substantia reticularis grisea. 



which take up a very pale stain in haematoxylin. Most of 

 these intrinsic cells are neurones of Golgi's type II, whose 

 processes do not extend beyond the lobe. Along the dorsal 

 and lateral borders of the lobe is a layer containing larger 

 cells whose nuclei stain very little in haematoxylin and whose 

 cytoplasm practically not at all. The axones of these cells con- 

 stitute the chief sensory conduction paths from the vagal lobe 

 to other parts of the brain, and I shall term them the dorsal 



