Herrick, Brain of the Codfish. 71 



The subdivision of the vagal lobe of Gadus into median and lateral lobules is mentioned in the 

 catalogue of the Museum of the Royal College of Surgeons of London (Burne'oz p. 93) but unfortu- 

 nately in the absence of aknowledgeof the internal structure Mr. BuRNE here was led by external appear- 

 ances and by the previous figures of Lota by Goronowitsch ('96) into error in the interpretation of 

 this region Jn the two dissections of the brain of the codfish there figured and in the accompanying 

 text the true vagal lobes are termed facial lobes and the somatic commissural and funicular nucleus 

 complex of my descriptions is termed lobus vagi and is said to give rise to the sensory roots of the 

 vagus nerve, Examination of the internal courses of these nerves at once corrects this mistake. The 

 dissections of the codfish brain figured in T. J. Parker's Zootomy ('00, p. 125) show the vagal lobes 

 very small with no designation. The "lobi posteriores," which might be mistaken for the vagal 

 lobes, are the tubercula acustica. The excellent series of transections of the codfish brniu given by 

 Kappers ('06) extends back only to the cephalic end of the vagal lobe. Fig. 4 of the present paper is 

 from a section taken a short distance caudad of Fig. xcix of Plate VII of Kappers' memoir. 



In Fig. 3 I present a photograph of this region of the brain of a large codfish (Gadus morrhua), 

 whose internal connections are as shown in Fig. 2. From the figure and description of Goronowitsch, 

 I have no doubt that the relations are essentially similar in Lota. 



The central tracts leading from the median lobule are the same 

 as those from the vagal lobe in other fishes; and caudad this lobe 

 merges into the visceral commissural nucleus of Cajal in the 

 typical way. The lateral lobule, v^hich receives only facialis 

 fibers, is wholly unlike the facial lobe of the siluroid and 

 cyprinoid fishes in its secondary connections. It contributes 

 few, if any, fibers to the long ascending secondary gustatory tract, 

 this tract being derived from the median lobule (Fig. 4). More- 

 over, there does not arise from any part of the vagal lobe a large, 

 clearly defined descending secondary gustatory tract, like that 

 from the facial lobe in Ameiurus and Cyprinus, entering the 

 dorso-lateral fasciculus for the funicular nucleus region and 

 spinal cord. The lateral lobule is directly continuous caudad with 

 the funicular nucleus region. A considerable tract of delicately 

 medullated fibers accumulates on the ventro-lateral border of the 

 lateral lobule and passes directly back to enter the cephalic end 

 of the funicular nucleus where it joins the substantia gelatinosa 

 Rolandi. My Wiegert sections do not show positively whether 

 these fibers are ascending or descending, but I assume the latter 

 by analogy; for this tract seems to correspond with the descending 

 secondary gustatory tract from the facial lobe of Ameiurus. But 

 in the cod this is a small and unimportant tract. 



The chief secondary connection of the lateral lobule is by a very 

 strong and heavily medullated tract which passes from its entire 

 extent into the ventral commissure and enters the ventral funiculi 

 of the same and the opposite side. These appear to be descend- 



