Herrick, Brain of the Codfish. 75 



vides a shorter path from taste buds on the fins to the muscles 

 which move the fins and the body as a whole. 



THE COMMISSURA INFIMA AND FUNICULAR NUCLEI OF GADUS. 



The analysis of the region of the commissura infima Halleri and 

 funicular nuclei is much more difficult in Gadus than in some 

 other types where the visceral and somatic elements of this com- 

 plex are more highly differentiated, as in Ameiurus. For the 

 typical arrangement and nomenclature of these parts the reader 

 is referred to my recent paper ('06) on the centers .for taste and 

 touch in Ameiurus and to Fig. i of the present article, which 

 summarizes the chief conclusions reached in that inquiry. 



The somatic division of the commissura infima of Gadus is 

 large and heavily medullated; the visceral division is unmeduUated. 

 The commissural nucleus is large and the somatic part is more 

 extensive than the visceral. 



The median lobule of the vagal lobe passes directly back into 

 the visceral commissural nucleus, which occupies the mid-dorsal 

 line caudad of the vagal lobes (Figs. 3 and 5). This nucleus con- 

 tains no medullated fibers; it does, however, contain many small 

 cells and a dense neuropil of unmeduUated fibers, many of which 

 cross the median line, forming the most cephalic part of the com- 

 missura infima. The nucleus ambiguus lies below it and gives 

 rise to motor roots of the vagus. The most caudal sensory root 

 of the vagus is seen in Fig. 5 entering the caudal tip of the vagal 

 lobe laterally of the commissural nucleus. In the Weigert sections 

 of young fish here examined (the specimens were about 7 cm. 

 long) no vagus root fibers are seen to enter the commissura infima. 

 In this, I confirm the statements made for Gadus by Kappers 

 ('06), who also worked with Weigert preparations. It is, however, 

 by no means clear from my preparations that no unmeduUated 

 termini of these root fibers cross in the commissure. In fact, the 

 appearance of the sections strongly suggests that this is the case, as 

 I have also found it in both Ameiurus and Cyprinus. 



Immediately behind the last sensory root of the vagus the soma- 

 tic commissural nucleus fills the wide space embraced between the 

 spinal V tracts and their nuclei of the two sides, and is composed of 

 dense neuropil, large cells and medullated fibers in very complex 



